Merge branch 'master' into Basilisk-release

41 files changed, 250 insertions, 1166 deletions

diff --git a/js/public/Value.h b/js/public/Value.h
index a40e65c83..01666ed4e 100644
--- a/js/public/Value.h
+++ b/js/public/Value.h
@@ -140,12 +140,16 @@ static_assert(sizeof(JSValueShiftedTag) == sizeof(uint64_t),
 
 #define JSVAL_TYPE_TO_TAG(type)      ((JSValueTag)(JSVAL_TAG_CLEAR | (type)))
 
+#define JSVAL_RAW64_UNDEFINED        (uint64_t(JSVAL_TAG_UNDEFINED) << 32)
+
 #define JSVAL_UPPER_EXCL_TAG_OF_PRIMITIVE_SET           JSVAL_TAG_OBJECT
 #define JSVAL_UPPER_INCL_TAG_OF_NUMBER_SET              JSVAL_TAG_INT32
 #define JSVAL_LOWER_INCL_TAG_OF_GCTHING_SET             JSVAL_TAG_STRING
 
 #elif defined(JS_PUNBOX64)
 
+#define JSVAL_RAW64_UNDEFINED        (uint64_t(JSVAL_TAG_UNDEFINED) << JSVAL_TAG_SHIFT)
+
 #define JSVAL_PAYLOAD_MASK           0x00007FFFFFFFFFFFLL
 #define JSVAL_TAG_MASK               0xFFFF800000000000LL
 #define JSVAL_TYPE_TO_TAG(type)      ((JSValueTag)(JSVAL_TAG_MAX_DOUBLE | (type)))
@@ -817,7 +821,7 @@ class MOZ_NON_PARAM alignas(8) Value
         double asDouble;
         void* asPtr;
 
-        layout() = default;
+        layout() : asBits(JSVAL_RAW64_UNDEFINED) {}
         explicit constexpr layout(uint64_t bits) : asBits(bits) {}
         explicit constexpr layout(double d) : asDouble(d) {}
     } data;
@@ -843,7 +847,7 @@ class MOZ_NON_PARAM alignas(8) Value
         size_t asWord;
         uintptr_t asUIntPtr;
 
-        layout() = default;
+        layout() : asBits(JSVAL_RAW64_UNDEFINED) {}
         explicit constexpr layout(uint64_t bits) : asBits(bits) {}
         explicit constexpr layout(double d) : asDouble(d) {}
     } data;
@@ -871,7 +875,7 @@ class MOZ_NON_PARAM alignas(8) Value
         double asDouble;
         void* asPtr;
 
-        layout() = default;
+        layout() : asBits(JSVAL_RAW64_UNDEFINED) {}
         explicit constexpr layout(uint64_t bits) : asBits(bits) {}
         explicit constexpr layout(double d) : asDouble(d) {}
     } data;
@@ -895,7 +899,7 @@ class MOZ_NON_PARAM alignas(8) Value
         size_t asWord;
         uintptr_t asUIntPtr;
 
-        layout() = default;
+        layout() : asBits(JSVAL_RAW64_UNDEFINED) {}
         explicit constexpr layout(uint64_t bits) : asBits(bits) {}
         explicit constexpr layout(double d) : asDouble(d) {}
     } data;
@@ -948,8 +952,51 @@ class MOZ_NON_PARAM alignas(8) Value
     }
 } JS_HAZ_GC_POINTER;
 
+/**
+ * This is a null-constructible structure that can convert to and from
+ * a Value, allowing UninitializedValue to be stored in unions.
+ */
+struct MOZ_NON_PARAM alignas(8) UninitializedValue
+{
+  private:
+    uint64_t bits;
+
+  public:
+    UninitializedValue() = default;
+    UninitializedValue(const UninitializedValue&) = default;
+    MOZ_IMPLICIT UninitializedValue(const Value& val) : bits(val.asRawBits()) {}
+
+    inline uint64_t asRawBits() const {
+        return bits;
+    }
+
+    inline Value& asValueRef() {
+        return *reinterpret_cast<Value*>(this);
+    }
+    inline const Value& asValueRef() const {
+        return *reinterpret_cast<const Value*>(this);
+    }
+
+    inline operator Value&() {
+        return asValueRef();
+    }
+    inline operator Value const&() const {
+        return asValueRef();
+    }
+    inline operator Value() const {
+        return asValueRef();
+    }
+
+    inline void operator=(Value const& other) {
+        asValueRef() = other;
+    }
+};
+
 static_assert(sizeof(Value) == 8, "Value size must leave three tag bits, be a binary power, and is ubiquitously depended upon everywhere");
 
+static_assert(sizeof(UninitializedValue) == sizeof(Value), "Value and UninitializedValue must be the same size");
+static_assert(alignof(UninitializedValue) == alignof(Value), "Value and UninitializedValue must have same alignment");
+
 inline bool
 IsOptimizedPlaceholderMagicValue(const Value& v)
 {
diff --git a/js/src/aclocal.m4 b/js/src/aclocal.m4
index 627837a41..abbbd4873 100644
--- a/js/src/aclocal.m4
+++ b/js/src/aclocal.m4
@@ -25,7 +25,6 @@ builtin(include, ../../build/autoconf/zlib.m4)dnl
 builtin(include, ../../build/autoconf/icu.m4)dnl
 builtin(include, ../../build/autoconf/clang-plugin.m4)dnl
 builtin(include, ../../build/autoconf/alloc.m4)dnl
-builtin(include, ../../build/autoconf/jemalloc.m4)dnl
 builtin(include, ../../build/autoconf/sanitize.m4)dnl
 builtin(include, ../../build/autoconf/ios.m4)dnl
 
diff --git a/js/src/builtin/Array.js b/js/src/builtin/Array.js
index 45f90a7b8..360dd2af1 100644
--- a/js/src/builtin/Array.js
+++ b/js/src/builtin/Array.js
@@ -900,11 +900,7 @@ function ArrayToLocaleString(locales, options) {
     if (firstElement === undefined || firstElement === null) {
         R = "";
     } else {
-#if EXPOSE_INTL_API
         R = ToString(callContentFunction(firstElement.toLocaleString, firstElement, locales, options));
-#else
-        R = ToString(callContentFunction(firstElement.toLocaleString, firstElement));
-#endif
     }
 
     // Step 3 (reordered).
@@ -919,11 +915,7 @@ function ArrayToLocaleString(locales, options) {
         // Steps 9.a, 9.c-e.
         R += separator;
         if (!(nextElement === undefined || nextElement === null)) {
-#if EXPOSE_INTL_API
             R += ToString(callContentFunction(nextElement.toLocaleString, nextElement, locales, options));
-#else
-            R += ToString(callContentFunction(nextElement.toLocaleString, nextElement));
-#endif
         }
     }
 
diff --git a/js/src/builtin/Intl.cpp b/js/src/builtin/Intl.cpp
index cd808cb10..71f7b58d4 100644
--- a/js/src/builtin/Intl.cpp
+++ b/js/src/builtin/Intl.cpp
@@ -23,7 +23,6 @@
 #include "jsobj.h"
 
 #include "builtin/IntlTimeZoneData.h"
-#if ENABLE_INTL_API
 #include "unicode/ucal.h"
 #include "unicode/ucol.h"
 #include "unicode/udat.h"
@@ -32,7 +31,6 @@
 #include "unicode/unum.h"
 #include "unicode/unumsys.h"
 #include "unicode/ustring.h"
-#endif
 #include "vm/DateTime.h"
 #include "vm/GlobalObject.h"
 #include "vm/Interpreter.h"
@@ -60,603 +58,6 @@ using mozilla::PodCopy;
  * http://userguide.icu-project.org/design#TOC-Error-Handling
  */
 
-
-/******************** ICU stubs ********************/
-
-#if !ENABLE_INTL_API
-
-/*
- * When the Internationalization API isn't enabled, we also shouldn't link
- * against ICU. However, we still want to compile this code in order to prevent
- * bit rot. The following stub implementations for ICU functions make this
- * possible. The functions using them should never be called, so they assert
- * and return error codes. Signatures adapted from ICU header files locid.h,
- * numsys.h, ucal.h, ucol.h, udat.h, udatpg.h, uenum.h, unum.h; see the ICU
- * directory for license.
- */
-
-typedef bool UBool;
-typedef char16_t UChar;
-typedef double UDate;
-
-enum UErrorCode {
-    U_ZERO_ERROR,
-    U_BUFFER_OVERFLOW_ERROR,
-};
-
-static inline UBool
-U_FAILURE(UErrorCode code)
-{
-    MOZ_CRASH("U_FAILURE: Intl API disabled");
-}
-
-inline const UChar*
-Char16ToUChar(const char16_t* chars)
-{
-    MOZ_CRASH("Char16ToUChar: Intl API disabled");
-}
-
-inline UChar*
-Char16ToUChar(char16_t* chars)
-{
-    MOZ_CRASH("Char16ToUChar: Intl API disabled");
-}
-
-inline char16_t*
-UCharToChar16(UChar* chars)
-{
-    MOZ_CRASH("UCharToChar16: Intl API disabled");
-}
-
-inline const char16_t*
-UCharToChar16(const UChar* chars)
-{
-    MOZ_CRASH("UCharToChar16: Intl API disabled");
-}
-
-static int32_t
-u_strlen(const UChar* s)
-{
-    MOZ_CRASH("u_strlen: Intl API disabled");
-}
-
-struct UEnumeration;
-
-static int32_t
-uenum_count(UEnumeration* en, UErrorCode* status)
-{
-    MOZ_CRASH("uenum_count: Intl API disabled");
-}
-
-static const char*
-uenum_next(UEnumeration* en, int32_t* resultLength, UErrorCode* status)
-{
-    MOZ_CRASH("uenum_next: Intl API disabled");
-}
-
-static void
-uenum_close(UEnumeration* en)
-{
-    MOZ_CRASH("uenum_close: Intl API disabled");
-}
-
-struct UCollator;
-
-enum UColAttribute {
-    UCOL_ALTERNATE_HANDLING,
-    UCOL_CASE_FIRST,
-    UCOL_CASE_LEVEL,
-    UCOL_NORMALIZATION_MODE,
-    UCOL_STRENGTH,
-    UCOL_NUMERIC_COLLATION,
-};
-
-enum UColAttributeValue {
-    UCOL_DEFAULT = -1,
-    UCOL_PRIMARY = 0,
-    UCOL_SECONDARY = 1,
-    UCOL_TERTIARY = 2,
-    UCOL_OFF = 16,
-    UCOL_ON = 17,
-    UCOL_SHIFTED = 20,
-    UCOL_LOWER_FIRST = 24,
-    UCOL_UPPER_FIRST = 25,
-};
-
-enum UCollationResult {
-    UCOL_EQUAL = 0,
-    UCOL_GREATER = 1,
-    UCOL_LESS = -1
-};
-
-static int32_t
-ucol_countAvailable()
-{
-    MOZ_CRASH("ucol_countAvailable: Intl API disabled");
-}
-
-static const char*
-ucol_getAvailable(int32_t localeIndex)
-{
-    MOZ_CRASH("ucol_getAvailable: Intl API disabled");
-}
-
-static UCollator*
-ucol_open(const char* loc, UErrorCode* status)
-{
-    MOZ_CRASH("ucol_open: Intl API disabled");
-}
-
-static void
-ucol_setAttribute(UCollator* coll, UColAttribute attr, UColAttributeValue value, UErrorCode* status)
-{
-    MOZ_CRASH("ucol_setAttribute: Intl API disabled");
-}
-
-static UCollationResult
-ucol_strcoll(const UCollator* coll, const UChar* source, int32_t sourceLength,
-             const UChar* target, int32_t targetLength)
-{
-    MOZ_CRASH("ucol_strcoll: Intl API disabled");
-}
-
-static void
-ucol_close(UCollator* coll)
-{
-    MOZ_CRASH("ucol_close: Intl API disabled");
-}
-
-static UEnumeration*
-ucol_getKeywordValuesForLocale(const char* key, const char* locale, UBool commonlyUsed,
-                               UErrorCode* status)
-{
-    MOZ_CRASH("ucol_getKeywordValuesForLocale: Intl API disabled");
-}
-
-struct UParseError;
-struct UFieldPosition;
-struct UFieldPositionIterator;
-typedef void* UNumberFormat;
-
-enum UNumberFormatStyle {
-    UNUM_DECIMAL = 1,
-    UNUM_CURRENCY,
-    UNUM_PERCENT,
-    UNUM_CURRENCY_ISO,
-    UNUM_CURRENCY_PLURAL,
-};
-
-enum UNumberFormatRoundingMode {
-    UNUM_ROUND_HALFUP,
-};
-
-enum UNumberFormatAttribute {
-    UNUM_GROUPING_USED,
-    UNUM_MIN_INTEGER_DIGITS,
-    UNUM_MAX_FRACTION_DIGITS,
-    UNUM_MIN_FRACTION_DIGITS,
-    UNUM_ROUNDING_MODE,
-    UNUM_SIGNIFICANT_DIGITS_USED,
-    UNUM_MIN_SIGNIFICANT_DIGITS,
-    UNUM_MAX_SIGNIFICANT_DIGITS,
-};
-
-enum UNumberFormatTextAttribute {
-    UNUM_CURRENCY_CODE,
-};
-
-static int32_t
-unum_countAvailable()
-{
-    MOZ_CRASH("unum_countAvailable: Intl API disabled");
-}
-
-static const char*
-unum_getAvailable(int32_t localeIndex)
-{
-    MOZ_CRASH("unum_getAvailable: Intl API disabled");
-}
-
-static UNumberFormat*
-unum_open(UNumberFormatStyle style, const UChar* pattern, int32_t patternLength,
-          const char* locale, UParseError* parseErr, UErrorCode* status)
-{
-    MOZ_CRASH("unum_open: Intl API disabled");
-}
-
-static void
-unum_setAttribute(UNumberFormat* fmt, UNumberFormatAttribute  attr, int32_t newValue)
-{
-    MOZ_CRASH("unum_setAttribute: Intl API disabled");
-}
-
-static int32_t
-unum_formatDouble(const UNumberFormat* fmt, double number, UChar* result,
-                  int32_t resultLength, UFieldPosition* pos, UErrorCode* status)
-{
-    MOZ_CRASH("unum_formatDouble: Intl API disabled");
-}
-
-static void
-unum_close(UNumberFormat* fmt)
-{
-    MOZ_CRASH("unum_close: Intl API disabled");
-}
-
-static void
-unum_setTextAttribute(UNumberFormat* fmt, UNumberFormatTextAttribute tag, const UChar* newValue,
-                      int32_t newValueLength, UErrorCode* status)
-{
-    MOZ_CRASH("unum_setTextAttribute: Intl API disabled");
-}
-
-typedef void* UNumberingSystem;
-
-static UNumberingSystem*
-unumsys_open(const char* locale, UErrorCode* status)
-{
-    MOZ_CRASH("unumsys_open: Intl API disabled");
-}
-
-static const char*
-unumsys_getName(const UNumberingSystem* unumsys)
-{
-    MOZ_CRASH("unumsys_getName: Intl API disabled");
-}
-
-static void
-unumsys_close(UNumberingSystem* unumsys)
-{
-    MOZ_CRASH("unumsys_close: Intl API disabled");
-}
-
-typedef void* UCalendar;
-
-enum UCalendarType {
-    UCAL_TRADITIONAL,
-    UCAL_DEFAULT = UCAL_TRADITIONAL,
-    UCAL_GREGORIAN
-};
-
-enum UCalendarAttribute {
-    UCAL_FIRST_DAY_OF_WEEK,
-    UCAL_MINIMAL_DAYS_IN_FIRST_WEEK
-};
-
-enum UCalendarDaysOfWeek {
-    UCAL_SUNDAY,
-    UCAL_MONDAY,
-    UCAL_TUESDAY,
-    UCAL_WEDNESDAY,
-    UCAL_THURSDAY,
-    UCAL_FRIDAY,
-    UCAL_SATURDAY
-};
-
-enum UCalendarWeekdayType {
-    UCAL_WEEKDAY,
-    UCAL_WEEKEND,
-    UCAL_WEEKEND_ONSET,
-    UCAL_WEEKEND_CEASE
-};
-
-enum UCalendarDateFields {
-    UCAL_ERA,
-    UCAL_YEAR,
-    UCAL_MONTH,
-    UCAL_WEEK_OF_YEAR,
-    UCAL_WEEK_OF_MONTH,
-    UCAL_DATE,
-    UCAL_DAY_OF_YEAR,
-    UCAL_DAY_OF_WEEK,
-    UCAL_DAY_OF_WEEK_IN_MONTH,
-    UCAL_AM_PM,
-    UCAL_HOUR,
-    UCAL_HOUR_OF_DAY,
-    UCAL_MINUTE,
-    UCAL_SECOND,
-    UCAL_MILLISECOND,
-    UCAL_ZONE_OFFSET,
-    UCAL_DST_OFFSET,
-    UCAL_YEAR_WOY,
-    UCAL_DOW_LOCAL,
-    UCAL_EXTENDED_YEAR,
-    UCAL_JULIAN_DAY,
-    UCAL_MILLISECONDS_IN_DAY,
-    UCAL_IS_LEAP_MONTH,
-    UCAL_FIELD_COUNT,
-    UCAL_DAY_OF_MONTH = UCAL_DATE
-};
-
-enum UCalendarMonths {
-  UCAL_JANUARY,
-  UCAL_FEBRUARY,
-  UCAL_MARCH,
-  UCAL_APRIL,
-  UCAL_MAY,
-  UCAL_JUNE,
-  UCAL_JULY,
-  UCAL_AUGUST,
-  UCAL_SEPTEMBER,
-  UCAL_OCTOBER,
-  UCAL_NOVEMBER,
-  UCAL_DECEMBER,
-  UCAL_UNDECIMBER
-};
-
-enum UCalendarAMPMs {
-  UCAL_AM,
-  UCAL_PM
-};
-
-static UCalendar*
-ucal_open(const UChar* zoneID, int32_t len, const char* locale,
-          UCalendarType type, UErrorCode* status)
-{
-    MOZ_CRASH("ucal_open: Intl API disabled");
-}
-
-static const char*
-ucal_getType(const UCalendar* cal, UErrorCode* status)
-{
-    MOZ_CRASH("ucal_getType: Intl API disabled");
-}
-
-static UEnumeration*
-ucal_getKeywordValuesForLocale(const char* key, const char* locale,
-                               UBool commonlyUsed, UErrorCode* status)
-{
-    MOZ_CRASH("ucal_getKeywordValuesForLocale: Intl API disabled");
-}
-
-static void
-ucal_close(UCalendar* cal)
-{
-    MOZ_CRASH("ucal_close: Intl API disabled");
-}
-
-static UCalendarWeekdayType
-ucal_getDayOfWeekType(const UCalendar *cal, UCalendarDaysOfWeek dayOfWeek, UErrorCode* status)
-{
-    MOZ_CRASH("ucal_getDayOfWeekType: Intl API disabled");
-}
-
-static int32_t
-ucal_getAttribute(const UCalendar*    cal,
-                  UCalendarAttribute  attr)
-{
-    MOZ_CRASH("ucal_getAttribute: Intl API disabled");
-}
-
-static int32_t
-ucal_get(const UCalendar *cal, UCalendarDateFields field, UErrorCode *status)
-{
-    MOZ_CRASH("ucal_get: Intl API disabled");
-}
-
-static UEnumeration*
-ucal_openTimeZones(UErrorCode* status)
-{
-    MOZ_CRASH("ucal_openTimeZones: Intl API disabled");
-}
-
-static int32_t
-ucal_getCanonicalTimeZoneID(const UChar* id, int32_t len, UChar* result, int32_t resultCapacity,
-                            UBool* isSystemID, UErrorCode* status)
-{
-    MOZ_CRASH("ucal_getCanonicalTimeZoneID: Intl API disabled");
-}
-
-static int32_t
-ucal_getDefaultTimeZone(UChar* result, int32_t resultCapacity, UErrorCode* status)
-{
-    MOZ_CRASH("ucal_getDefaultTimeZone: Intl API disabled");
-}
-
-enum UDateTimePatternField {
-    UDATPG_YEAR_FIELD,
-    UDATPG_MONTH_FIELD,
-    UDATPG_WEEK_OF_YEAR_FIELD,
-    UDATPG_DAY_FIELD,
-};
-
-typedef void* UDateTimePatternGenerator;
-
-static UDateTimePatternGenerator*
-udatpg_open(const char* locale, UErrorCode* pErrorCode)
-{
-    MOZ_CRASH("udatpg_open: Intl API disabled");
-}
-
-static int32_t
-udatpg_getBestPattern(UDateTimePatternGenerator* dtpg, const UChar* skeleton,
-                      int32_t length, UChar* bestPattern, int32_t capacity,
-                      UErrorCode* pErrorCode)
-{
-    MOZ_CRASH("udatpg_getBestPattern: Intl API disabled");
-}
-
-static const UChar *
-udatpg_getAppendItemName(const UDateTimePatternGenerator *dtpg,
-                         UDateTimePatternField field,
-                         int32_t *pLength)
-{
-    MOZ_CRASH("udatpg_getAppendItemName: Intl API disabled");
-}
-
-static void
-udatpg_close(UDateTimePatternGenerator* dtpg)
-{
-    MOZ_CRASH("udatpg_close: Intl API disabled");
-}
-
-typedef void* UCalendar;
-typedef void* UDateFormat;
-
-enum UDateFormatField {
-    UDAT_ERA_FIELD = 0,
-    UDAT_YEAR_FIELD = 1,
-    UDAT_MONTH_FIELD = 2,
-    UDAT_DATE_FIELD = 3,
-    UDAT_HOUR_OF_DAY1_FIELD = 4,
-    UDAT_HOUR_OF_DAY0_FIELD = 5,
-    UDAT_MINUTE_FIELD = 6,
-    UDAT_SECOND_FIELD = 7,
-    UDAT_FRACTIONAL_SECOND_FIELD = 8,
-    UDAT_DAY_OF_WEEK_FIELD = 9,
-    UDAT_DAY_OF_YEAR_FIELD = 10,
-    UDAT_DAY_OF_WEEK_IN_MONTH_FIELD = 11,
-    UDAT_WEEK_OF_YEAR_FIELD = 12,
-    UDAT_WEEK_OF_MONTH_FIELD = 13,
-    UDAT_AM_PM_FIELD = 14,
-    UDAT_HOUR1_FIELD = 15,
-    UDAT_HOUR0_FIELD = 16,
-    UDAT_TIMEZONE_FIELD = 17,
-    UDAT_YEAR_WOY_FIELD = 18,
-    UDAT_DOW_LOCAL_FIELD = 19,
-    UDAT_EXTENDED_YEAR_FIELD = 20,
-    UDAT_JULIAN_DAY_FIELD = 21,
-    UDAT_MILLISECONDS_IN_DAY_FIELD = 22,
-    UDAT_TIMEZONE_RFC_FIELD = 23,
-    UDAT_TIMEZONE_GENERIC_FIELD = 24,
-    UDAT_STANDALONE_DAY_FIELD = 25,
-    UDAT_STANDALONE_MONTH_FIELD = 26,
-    UDAT_QUARTER_FIELD = 27,
-    UDAT_STANDALONE_QUARTER_FIELD = 28,
-    UDAT_TIMEZONE_SPECIAL_FIELD = 29,
-    UDAT_YEAR_NAME_FIELD = 30,
-    UDAT_TIMEZONE_LOCALIZED_GMT_OFFSET_FIELD = 31,
-    UDAT_TIMEZONE_ISO_FIELD = 32,
-    UDAT_TIMEZONE_ISO_LOCAL_FIELD = 33,
-    UDAT_RELATED_YEAR_FIELD = 34,
-    UDAT_AM_PM_MIDNIGHT_NOON_FIELD = 35,
-    UDAT_FLEXIBLE_DAY_PERIOD_FIELD = 36,
-    UDAT_TIME_SEPARATOR_FIELD = 37,
-    UDAT_FIELD_COUNT = 38
-};
-
-enum UDateFormatStyle {
-    UDAT_FULL,
-    UDAT_LONG,
-    UDAT_MEDIUM,
-    UDAT_SHORT,
-    UDAT_DEFAULT = UDAT_MEDIUM,
-    UDAT_PATTERN = -2,
-    UDAT_IGNORE = UDAT_PATTERN
-};
-
-enum UDateFormatSymbolType {
-    UDAT_ERAS,
-    UDAT_MONTHS,
-    UDAT_SHORT_MONTHS,
-    UDAT_WEEKDAYS,
-    UDAT_SHORT_WEEKDAYS,
-    UDAT_AM_PMS,
-    UDAT_LOCALIZED_CHARS,
-    UDAT_ERA_NAMES,
-    UDAT_NARROW_MONTHS,
-    UDAT_NARROW_WEEKDAYS,
-    UDAT_STANDALONE_MONTHS,
-    UDAT_STANDALONE_SHORT_MONTHS,
-    UDAT_STANDALONE_NARROW_MONTHS,
-    UDAT_STANDALONE_WEEKDAYS,
-    UDAT_STANDALONE_SHORT_WEEKDAYS,
-    UDAT_STANDALONE_NARROW_WEEKDAYS,
-    UDAT_QUARTERS,
-    UDAT_SHORT_QUARTERS,
-    UDAT_STANDALONE_QUARTERS,
-    UDAT_STANDALONE_SHORT_QUARTERS,
-    UDAT_SHORTER_WEEKDAYS,
-    UDAT_STANDALONE_SHORTER_WEEKDAYS,
-    UDAT_CYCLIC_YEARS_WIDE,
-    UDAT_CYCLIC_YEARS_ABBREVIATED,
-    UDAT_CYCLIC_YEARS_NARROW,
-    UDAT_ZODIAC_NAMES_WIDE,
-    UDAT_ZODIAC_NAMES_ABBREVIATED,
-    UDAT_ZODIAC_NAMES_NARROW
-};
-
-static int32_t
-udat_countAvailable()
-{
-    MOZ_CRASH("udat_countAvailable: Intl API disabled");
-}
-
-static const char*
-udat_getAvailable(int32_t localeIndex)
-{
-    MOZ_CRASH("udat_getAvailable: Intl API disabled");
-}
-
-static UDateFormat*
-udat_open(UDateFormatStyle timeStyle, UDateFormatStyle dateStyle, const char* locale,
-          const UChar* tzID, int32_t tzIDLength, const UChar* pattern,
-          int32_t patternLength, UErrorCode* status)
-{
-    MOZ_CRASH("udat_open: Intl API disabled");
-}
-
-static const UCalendar*
-udat_getCalendar(const UDateFormat* fmt)
-{
-    MOZ_CRASH("udat_getCalendar: Intl API disabled");
-}
-
-static void
-ucal_setGregorianChange(UCalendar* cal, UDate date, UErrorCode* pErrorCode)
-{
-    MOZ_CRASH("ucal_setGregorianChange: Intl API disabled");
-}
-
-static int32_t
-udat_format(const UDateFormat* format, UDate dateToFormat, UChar* result,
-            int32_t resultLength, UFieldPosition* position, UErrorCode* status)
-{
-    MOZ_CRASH("udat_format: Intl API disabled");
-}
-
-static int32_t
-udat_formatForFields(const UDateFormat* format, UDate dateToFormat,
-                     UChar* result, int32_t resultLength, UFieldPositionIterator* fpositer,
-                     UErrorCode* status)
-{
-    MOZ_CRASH("udat_formatForFields: Intl API disabled");
-}
-
-static UFieldPositionIterator*
-ufieldpositer_open(UErrorCode* status)
-{
-    MOZ_CRASH("ufieldpositer_open: Intl API disabled");
-}
-
-static void
-ufieldpositer_close(UFieldPositionIterator* fpositer)
-{
-    MOZ_CRASH("ufieldpositer_close: Intl API disabled");
-}
-
-static int32_t
-ufieldpositer_next(UFieldPositionIterator* fpositer, int32_t* beginIndex, int32_t* endIndex)
-{
-    MOZ_CRASH("ufieldpositer_next: Intl API disabled");
-}
-
-static void
-udat_close(UDateFormat* format)
-{
-    MOZ_CRASH("udat_close: Intl API disabled");
-}
-
-static int32_t
-udat_getSymbols(const UDateFormat *fmt, UDateFormatSymbolType type, int32_t symbolIndex,
-                UChar *result, int32_t resultLength, UErrorCode *status)
-{
-    MOZ_CRASH("udat_getSymbols: Intl API disabled");
-}
-
-#endif
-
-
 /******************** Common to Intl constructors ********************/
 
 static bool
@@ -706,7 +107,6 @@ intl_availableLocales(JSContext* cx, CountAvailable countAvailable,
     if (!locales)
         return false;
 
-#if ENABLE_INTL_API
     uint32_t count = countAvailable();
     RootedValue t(cx, BooleanValue(true));
     for (uint32_t i = 0; i < count; i++) {
@@ -726,7 +126,7 @@ intl_availableLocales(JSContext* cx, CountAvailable countAvailable,
             return false;
         }
     }
-#endif
+
     result.setObject(*locales);
     return true;
 }
diff --git a/js/src/builtin/Intl.h b/js/src/builtin/Intl.h
index b2197060d..9a1e44913 100644
--- a/js/src/builtin/Intl.h
+++ b/js/src/builtin/Intl.h
@@ -16,9 +16,7 @@
 #include "js/GCAPI.h"
 #include "js/GCHashTable.h"
 
-#if ENABLE_INTL_API
 #include "unicode/utypes.h"
-#endif
 
 /*
  * The Intl module specified by standard ECMA-402,
@@ -429,7 +427,6 @@ intl_GetCalendarInfo(JSContext* cx, unsigned argc, Value* vp);
 extern MOZ_MUST_USE bool
 intl_ComputeDisplayNames(JSContext* cx, unsigned argc, Value* vp);
 
-#if ENABLE_INTL_API
 /**
  * Cast char16_t* strings to UChar* strings used by ICU.
  */
@@ -456,7 +453,6 @@ UCharToChar16(const UChar* chars)
 {
   return reinterpret_cast<const char16_t*>(chars);
 }
-#endif // ENABLE_INTL_API
 
 } // namespace js
 
diff --git a/js/src/builtin/Intl.js b/js/src/builtin/Intl.js
index 509168d7a..6391c3e70 100644
--- a/js/src/builtin/Intl.js
+++ b/js/src/builtin/Intl.js
@@ -9,7 +9,8 @@
          JSMSG_INVALID_OPTION_VALUE: false, JSMSG_INVALID_DIGITS_VALUE: false,
          JSMSG_INTL_OBJECT_REINITED: false, JSMSG_INVALID_CURRENCY_CODE: false,
          JSMSG_UNDEFINED_CURRENCY: false, JSMSG_INVALID_TIME_ZONE: false,
-         JSMSG_DATE_NOT_FINITE: false,
+         JSMSG_DATE_NOT_FINITE: false, JSMSG_INVALID_KEYS_TYPE: false,
+         JSMSG_INVALID_KEY: false,
          intl_Collator_availableLocales: false,
          intl_availableCollations: false,
          intl_CompareStrings: false,
@@ -3024,3 +3025,126 @@ function Intl_getCalendarInfo(locales) {
 
   return result;
 }
+
+/**
+ * This function is a custom method designed after Intl API, but currently
+ * not part of the spec or spec proposal.
+ * We want to use it internally to retrieve translated values from CLDR in
+ * order to ensure they're aligned with what Intl API returns.
+ *
+ * This API may one day be a foundation for an ECMA402 API spec proposal.
+ *
+ * The function takes two arguments - locales which is a list of locale strings
+ * and options which is an object with two optional properties:
+ *
+ *   keys:
+ *     an Array of string values that are paths to individual terms
+ *
+ *   style:
+ *     a String with a value "long", "short" or "narrow"
+ *
+ * It returns an object with properties:
+ *
+ *   locale:
+ *     a negotiated locale string
+ *
+ *   style:
+ *     negotiated style
+ *
+ *   values:
+ *     A key-value pair list of requested keys and corresponding
+ *     translated values
+ *
+ */
+function Intl_getDisplayNames(locales, options) {
+    // 1. Let requestLocales be ? CanonicalizeLocaleList(locales).
+    const requestedLocales = CanonicalizeLocaleList(locales);
+
+    // 2. If options is undefined, then
+    if (options === undefined)
+        // a. Let options be ObjectCreate(%ObjectPrototype%).
+        options = {};
+    // 3. Else,
+    else
+        // a. Let options be ? ToObject(options).
+        options = ToObject(options);
+
+    const DateTimeFormat = dateTimeFormatInternalProperties;
+
+    // 4. Let localeData be %DateTimeFormat%.[[localeData]].
+    const localeData = DateTimeFormat.localeData;
+
+    // 5. Let opt be a new Record.
+    const localeOpt = new Record();
+    // 6. Set localeOpt.[[localeMatcher]] to "best fit".
+    localeOpt.localeMatcher = "best fit";
+
+    // 7. Let r be ResolveLocale(%DateTimeFormat%.[[availableLocales]], requestedLocales, localeOpt,
+    //    %DateTimeFormat%.[[relevantExtensionKeys]], localeData).
+    const r = ResolveLocale(callFunction(DateTimeFormat.availableLocales, DateTimeFormat),
+                          requestedLocales,
+                          localeOpt,
+                          DateTimeFormat.relevantExtensionKeys,
+                          localeData);
+
+    // 8. Let style be ? GetOption(options, "style", "string", « "long", "short", "narrow" », "long").
+    const style = GetOption(options, "style", "string", ["long", "short", "narrow"], "long");
+    // 9. Let keys be ? Get(options, "keys").
+    let keys = options.keys;
+
+    // 10. If keys is undefined,
+    if (keys === undefined) {
+        // a. Let keys be ArrayCreate(0).
+        keys = [];
+    } else if (!IsObject(keys)) {
+        // 11. Else,
+        //   a. If Type(keys) is not Object, throw a TypeError exception.
+        ThrowTypeError(JSMSG_INVALID_KEYS_TYPE);
+    }
+
+    // 12. Let processedKeys be ArrayCreate(0).
+    // (This really should be a List, but we use an Array here in order that
+    // |intl_ComputeDisplayNames| may infallibly access the list's length via
+    // |ArrayObject::length|.)
+    let processedKeys = [];
+    // 13. Let len be ? ToLength(? Get(keys, "length")).
+    let len = ToLength(keys.length);
+    // 14. Let i be 0.
+    // 15. Repeat, while i < len
+    for (let i = 0; i < len; i++) {
+        // a. Let processedKey be ? ToString(? Get(keys, i)).
+        // b. Perform ? CreateDataPropertyOrThrow(processedKeys, i, processedKey).
+        callFunction(std_Array_push, processedKeys, ToString(keys[i]));
+    }
+
+    // 16. Let names be ? ComputeDisplayNames(r.[[locale]], style, processedKeys).
+    const names = intl_ComputeDisplayNames(r.locale, style, processedKeys);
+
+    // 17. Let values be ObjectCreate(%ObjectPrototype%).
+    const values = {};
+
+    // 18. Set i to 0.
+    // 19. Repeat, while i < len
+    for (let i = 0; i < len; i++) {
+        // a. Let key be ? Get(processedKeys, i).
+        const key = processedKeys[i];
+        // b. Let name be ? Get(names, i).
+        const name = names[i];
+        // c. Assert: Type(name) is string.
+        assert(typeof name === "string", "unexpected non-string value");
+        // d. Assert: the length of name is greater than zero.
+        assert(name.length > 0, "empty string value");
+        // e. Perform ? DefinePropertyOrThrow(values, key, name).
+        _DefineDataProperty(values, key, name);
+    }
+
+    // 20. Let options be ObjectCreate(%ObjectPrototype%).
+    // 21. Perform ! DefinePropertyOrThrow(result, "locale", r.[[locale]]).
+    // 22. Perform ! DefinePropertyOrThrow(result, "style", style).
+    // 23. Perform ! DefinePropertyOrThrow(result, "values", values).
+    const result = { locale: r.locale, style, values };
+
+    // 24. Return result.
+    return result;
+
+}
diff --git a/js/src/builtin/String.js b/js/src/builtin/String.js
index 4202d0de6..6d1d335a0 100644
--- a/js/src/builtin/String.js
+++ b/js/src/builtin/String.js
@@ -659,11 +659,7 @@ function String_static_localeCompare(str1, str2) {
         ThrowTypeError(JSMSG_MISSING_FUN_ARG, 0, "String.localeCompare");
     var locales = arguments.length > 2 ? arguments[2] : undefined;
     var options = arguments.length > 3 ? arguments[3] : undefined;
-#if EXPOSE_INTL_API
     return callFunction(String_localeCompare, str1, str2, locales, options);
-#else
-    return callFunction(std_String_localeCompare, str1, str2, locales, options);
-#endif
 }
 
 // ES6 draft 2014-04-27 B.2.3.3
@@ -855,14 +851,12 @@ function String_static_toLocaleUpperCase(string) {
     return callFunction(std_String_toLocaleUpperCase, string);
 }
 
-#if EXPOSE_INTL_API
 function String_static_normalize(string) {
     if (arguments.length < 1)
         ThrowTypeError(JSMSG_MISSING_FUN_ARG, 0, 'String.normalize');
     var form = arguments.length > 1 ? arguments[1] : undefined;
     return callFunction(std_String_normalize, string, form);
 }
-#endif
 
 function String_static_concat(string, arg1) {
     if (arguments.length < 1)
diff --git a/js/src/builtin/TestingFunctions.cpp b/js/src/builtin/TestingFunctions.cpp
index a14f9ba69..00637a7a5 100644
--- a/js/src/builtin/TestingFunctions.cpp
+++ b/js/src/builtin/TestingFunctions.cpp
@@ -236,11 +236,7 @@ GetBuildConfiguration(JSContext* cx, unsigned argc, Value* vp)
     if (!JS_SetProperty(cx, info, "binary-data", value))
         return false;
 
-#ifdef EXPOSE_INTL_API
     value = BooleanValue(true);
-#else
-    value = BooleanValue(false);
-#endif
     if (!JS_SetProperty(cx, info, "intl-api", value))
         return false;
 
diff --git a/js/src/builtin/TypedArray.js b/js/src/builtin/TypedArray.js
index a2205dc92..a1934051d 100644
--- a/js/src/builtin/TypedArray.js
+++ b/js/src/builtin/TypedArray.js
@@ -1232,11 +1232,7 @@ function TypedArrayToLocaleString(locales = undefined, options = undefined) {
     // Steps 6-7.
     // Omit the 'if' clause in step 6, since typed arrays can't have undefined
     // or null elements.
-#if EXPOSE_INTL_API
     var R = ToString(callContentFunction(firstElement.toLocaleString, firstElement, locales, options));
-#else
-    var R = ToString(callContentFunction(firstElement.toLocaleString, firstElement));
-#endif
 
     // Step 3 (reordered).
     // We don't (yet?) implement locale-dependent separators.
@@ -1258,11 +1254,7 @@ function TypedArrayToLocaleString(locales = undefined, options = undefined) {
         // the error message. So despite bug 1079853, we can skip step 9.c.
 
         // Step 9.d.
-#if EXPOSE_INTL_API
         R = ToString(callContentFunction(nextElement.toLocaleString, nextElement, locales, options));
-#else
-        R = ToString(callContentFunction(nextElement.toLocaleString, nextElement));
-#endif
 
         // Step 9.e.
         R = S + R;
diff --git a/js/src/gdb/moz.build b/js/src/gdb/moz.build
index 681f9807c..faa69eb7b 100644
--- a/js/src/gdb/moz.build
+++ b/js/src/gdb/moz.build
@@ -34,7 +34,7 @@ USE_LIBS += [
     'static:js',
 ]
 
-if CONFIG['ENABLE_INTL_API'] and CONFIG['MOZ_ICU_DATA_ARCHIVE']:
+if CONFIG['MOZ_ICU_DATA_ARCHIVE']:
     # The ICU libraries linked into libmozjs will not include the ICU data,
     # so link it directly.
     USE_LIBS += ['icudata']
diff --git a/js/src/jit/BaselineFrameInfo.h b/js/src/jit/BaselineFrameInfo.h
index 13bf0358d..1691270ac 100644
--- a/js/src/jit/BaselineFrameInfo.h
+++ b/js/src/jit/BaselineFrameInfo.h
@@ -67,7 +67,7 @@ class StackValue
 
     union {
         struct {
-            Value v;
+            JS::UninitializedValue v;
         } constant;
         struct {
             mozilla::AlignedStorage2<ValueOperand> reg;
@@ -112,7 +112,7 @@ class StackValue
     }
     Value constant() const {
         MOZ_ASSERT(kind_ == Constant);
-        return data.constant.v;
+        return data.constant.v.asValueRef();
     }
     ValueOperand reg() const {
         MOZ_ASSERT(kind_ == Register);
diff --git a/js/src/jit/RegisterSets.h b/js/src/jit/RegisterSets.h
index 0a4045dd7..08ae53f16 100644
--- a/js/src/jit/RegisterSets.h
+++ b/js/src/jit/RegisterSets.h
@@ -226,13 +226,13 @@ class ConstantOrRegister
 
     // Space to hold either a Value or a TypedOrValueRegister.
     union U {
-        Value constant;
+        JS::UninitializedValue constant;
         TypedOrValueRegister reg;
     } data;
 
-    const Value& dataValue() const {
+    Value dataValue() const {
         MOZ_ASSERT(constant());
-        return data.constant;
+        return data.constant.asValueRef();
     }
     void setDataValue(const Value& value) {
         MOZ_ASSERT(constant());
@@ -268,7 +268,7 @@ class ConstantOrRegister
         return constant_;
     }
 
-    const Value& value() const {
+    Value value() const {
         return dataValue();
     }
 
diff --git a/js/src/jit/RematerializedFrame.cpp b/js/src/jit/RematerializedFrame.cpp
index cb324220c..32fad1267 100644
--- a/js/src/jit/RematerializedFrame.cpp
+++ b/js/src/jit/RematerializedFrame.cpp
@@ -61,9 +61,17 @@ RematerializedFrame::New(JSContext* cx, uint8_t* top, InlineFrameIterator& iter,
 {
     unsigned numFormals = iter.isFunctionFrame() ? iter.calleeTemplate()->nargs() : 0;
     unsigned argSlots = Max(numFormals, iter.numActualArgs());
-    size_t numBytes = sizeof(RematerializedFrame) +
-        (argSlots + iter.script()->nfixed()) * sizeof(Value) -
-        sizeof(Value); // 1 Value included in sizeof(RematerializedFrame)
+    unsigned extraSlots = argSlots + iter.script()->nfixed();
+
+    // One Value slot is included in sizeof(RematerializedFrame), so we can
+    // reduce the extra slot count by one.  However, if there are zero slot
+    // allocations total, then reducing the slots by one will lead to
+    // the memory allocation being smaller  than sizeof(RematerializedFrame).
+    if (extraSlots > 0)
+        extraSlots -= 1;
+
+    size_t numBytes = sizeof(RematerializedFrame) + (extraSlots * sizeof(Value));
+    MOZ_ASSERT(numBytes >= sizeof(RematerializedFrame));
 
     void* buf = cx->pod_calloc<uint8_t>(numBytes);
     if (!buf)
diff --git a/js/src/jsapi-tests/moz.build b/js/src/jsapi-tests/moz.build
index f7a6080aa..277a145b0 100644
--- a/js/src/jsapi-tests/moz.build
+++ b/js/src/jsapi-tests/moz.build
@@ -135,7 +135,7 @@ LOCAL_INCLUDES += [
     '..',
 ]
 
-if CONFIG['ENABLE_INTL_API'] and CONFIG['MOZ_ICU_DATA_ARCHIVE']:
+if CONFIG['MOZ_ICU_DATA_ARCHIVE']:
     # The ICU libraries linked into libmozjs will not include the ICU data,
     # so link it directly.
     USE_LIBS += ['icudata']
diff --git a/js/src/jsapi.h b/js/src/jsapi.h
index 989abe47c..c1195cc00 100644
--- a/js/src/jsapi.h
+++ b/js/src/jsapi.h
@@ -5222,7 +5222,7 @@ JS_ResetDefaultLocale(JSContext* cx);
 struct JSLocaleCallbacks {
     JSLocaleToUpperCase     localeToUpperCase;
     JSLocaleToLowerCase     localeToLowerCase;
-    JSLocaleCompare         localeCompare; // not used #if EXPOSE_INTL_API
+    JSLocaleCompare         localeCompare; // not used
     JSLocaleToUnicode       localeToUnicode;
 };
 
diff --git a/js/src/jsdate.cpp b/js/src/jsdate.cpp
index 00a8abf84..52294a5df 100755
--- a/js/src/jsdate.cpp
+++ b/js/src/jsdate.cpp
@@ -2743,77 +2743,6 @@ ToLocaleFormatHelper(JSContext* cx, HandleObject obj, const char* format, Mutabl
     return true;
 }
 
-#if !EXPOSE_INTL_API
-/* ES5 15.9.5.5. */
-MOZ_ALWAYS_INLINE bool
-date_toLocaleString_impl(JSContext* cx, const CallArgs& args)
-{
-    /*
-     * Use '%#c' for windows, because '%c' is backward-compatible and non-y2k
-     * with msvc; '%#c' requests that a full year be used in the result string.
-     */
-    static const char format[] =
-#if defined(_WIN32) && !defined(__MWERKS__)
-                                   "%#c"
-#else
-                                   "%c"
-#endif
-                                   ;
-
-    Rooted<DateObject*> dateObj(cx, &args.thisv().toObject().as<DateObject>());
-    return ToLocaleFormatHelper(cx, dateObj, format, args.rval());
-}
-
-static bool
-date_toLocaleString(JSContext* cx, unsigned argc, Value* vp)
-{
-    CallArgs args = CallArgsFromVp(argc, vp);
-    return CallNonGenericMethod<IsDate, date_toLocaleString_impl>(cx, args);
-}
-
-/* ES5 15.9.5.6. */
-MOZ_ALWAYS_INLINE bool
-date_toLocaleDateString_impl(JSContext* cx, const CallArgs& args)
-{
-    /*
-     * Use '%#x' for windows, because '%x' is backward-compatible and non-y2k
-     * with msvc; '%#x' requests that a full year be used in the result string.
-     */
-    static const char format[] =
-#if defined(_WIN32) && !defined(__MWERKS__)
-                                   "%#x"
-#else
-                                   "%x"
-#endif
-                                   ;
-
-    Rooted<DateObject*> dateObj(cx, &args.thisv().toObject().as<DateObject>());
-    return ToLocaleFormatHelper(cx, dateObj, format, args.rval());
-}
-
-static bool
-date_toLocaleDateString(JSContext* cx, unsigned argc, Value* vp)
-{
-    CallArgs args = CallArgsFromVp(argc, vp);
-    return CallNonGenericMethod<IsDate, date_toLocaleDateString_impl>(cx, args);
-}
-
-/* ES5 15.9.5.7. */
-MOZ_ALWAYS_INLINE bool
-date_toLocaleTimeString_impl(JSContext* cx, const CallArgs& args)
-{
-    Rooted<DateObject*> dateObj(cx, &args.thisv().toObject().as<DateObject>());
-    return ToLocaleFormatHelper(cx, dateObj, "%X", args.rval());
-}
-
-static bool
-date_toLocaleTimeString(JSContext* cx, unsigned argc, Value* vp)
-{
-    CallArgs args = CallArgsFromVp(argc, vp);
-    return CallNonGenericMethod<IsDate, date_toLocaleTimeString_impl>(cx, args);
-}
-#endif /* !EXPOSE_INTL_API */
-
 MOZ_ALWAYS_INLINE bool
 date_toLocaleFormat_impl(JSContext* cx, const CallArgs& args)
 {
@@ -3037,15 +2966,9 @@ static const JSFunctionSpec date_methods[] = {
     JS_FN("setUTCMilliseconds",  date_setUTCMilliseconds, 1,0),
     JS_FN("toUTCString",         date_toGMTString,        0,0),
     JS_FN("toLocaleFormat",      date_toLocaleFormat,     0,0),
-#if EXPOSE_INTL_API
     JS_SELF_HOSTED_FN(js_toLocaleString_str, "Date_toLocaleString", 0,0),
     JS_SELF_HOSTED_FN("toLocaleDateString", "Date_toLocaleDateString", 0,0),
     JS_SELF_HOSTED_FN("toLocaleTimeString", "Date_toLocaleTimeString", 0,0),
-#else
-    JS_FN(js_toLocaleString_str, date_toLocaleString,     0,0),
-    JS_FN("toLocaleDateString",  date_toLocaleDateString, 0,0),
-    JS_FN("toLocaleTimeString",  date_toLocaleTimeString, 0,0),
-#endif
     JS_FN("toDateString",        date_toDateString,       0,0),
     JS_FN("toTimeString",        date_toTimeString,       0,0),
     JS_FN("toISOString",         date_toISOString,        0,0),
diff --git a/js/src/jsnum.cpp b/js/src/jsnum.cpp
index 8885737f7..28ed15159 100644
--- a/js/src/jsnum.cpp
+++ b/js/src/jsnum.cpp
@@ -724,141 +724,6 @@ js::num_toString(JSContext* cx, unsigned argc, Value* vp)
     return CallNonGenericMethod<IsNumber, num_toString_impl>(cx, args);
 }
 
-#if !EXPOSE_INTL_API
-MOZ_ALWAYS_INLINE bool
-num_toLocaleString_impl(JSContext* cx, const CallArgs& args)
-{
-    MOZ_ASSERT(IsNumber(args.thisv()));
-
-    double d = Extract(args.thisv());
-
-    RootedString str(cx, NumberToStringWithBase<CanGC>(cx, d, 10));
-    if (!str) {
-        JS_ReportOutOfMemory(cx);
-        return false;
-    }
-
-    /*
-     * Create the string, move back to bytes to make string twiddling
-     * a bit easier and so we can insert platform charset seperators.
-     */
-    JSAutoByteString numBytes(cx, str);
-    if (!numBytes)
-        return false;
-    const char* num = numBytes.ptr();
-    if (!num)
-        return false;
-
-    /*
-     * Find the first non-integer value, whether it be a letter as in
-     * 'Infinity', a decimal point, or an 'e' from exponential notation.
-     */
-    const char* nint = num;
-    if (*nint == '-')
-        nint++;
-    while (*nint >= '0' && *nint <= '9')
-        nint++;
-    int digits = nint - num;
-    const char* end = num + digits;
-    if (!digits) {
-        args.rval().setString(str);
-        return true;
-    }
-
-    JSRuntime* rt = cx->runtime();
-    size_t thousandsLength = strlen(rt->thousandsSeparator);
-    size_t decimalLength = strlen(rt->decimalSeparator);
-
-    /* Figure out how long resulting string will be. */
-    int buflen = strlen(num);
-    if (*nint == '.')
-        buflen += decimalLength - 1; /* -1 to account for existing '.' */
-
-    const char* numGrouping;
-    const char* tmpGroup;
-    numGrouping = tmpGroup = rt->numGrouping;
-    int remainder = digits;
-    if (*num == '-')
-        remainder--;
-
-    while (*tmpGroup != CHAR_MAX && *tmpGroup != '\0') {
-        if (*tmpGroup >= remainder)
-            break;
-        buflen += thousandsLength;
-        remainder -= *tmpGroup;
-        tmpGroup++;
-    }
-
-    int nrepeat;
-    if (*tmpGroup == '\0' && *numGrouping != '\0') {
-        nrepeat = (remainder - 1) / tmpGroup[-1];
-        buflen += thousandsLength * nrepeat;
-        remainder -= nrepeat * tmpGroup[-1];
-    } else {
-        nrepeat = 0;
-    }
-    tmpGroup--;
-
-    char* buf = cx->pod_malloc<char>(buflen + 1);
-    if (!buf)
-        return false;
-
-    char* tmpDest = buf;
-    const char* tmpSrc = num;
-
-    while (*tmpSrc == '-' || remainder--) {
-        MOZ_ASSERT(tmpDest - buf < buflen);
-        *tmpDest++ = *tmpSrc++;
-    }
-    while (tmpSrc < end) {
-        MOZ_ASSERT(tmpDest - buf + ptrdiff_t(thousandsLength) <= buflen);
-        strcpy(tmpDest, rt->thousandsSeparator);
-        tmpDest += thousandsLength;
-        MOZ_ASSERT(tmpDest - buf + *tmpGroup <= buflen);
-        js_memcpy(tmpDest, tmpSrc, *tmpGroup);
-        tmpDest += *tmpGroup;
-        tmpSrc += *tmpGroup;
-        if (--nrepeat < 0)
-            tmpGroup--;
-    }
-
-    if (*nint == '.') {
-        MOZ_ASSERT(tmpDest - buf + ptrdiff_t(decimalLength) <= buflen);
-        strcpy(tmpDest, rt->decimalSeparator);
-        tmpDest += decimalLength;
-        MOZ_ASSERT(tmpDest - buf + ptrdiff_t(strlen(nint + 1)) <= buflen);
-        strcpy(tmpDest, nint + 1);
-    } else {
-        MOZ_ASSERT(tmpDest - buf + ptrdiff_t(strlen(nint)) <= buflen);
-        strcpy(tmpDest, nint);
-    }
-
-    if (cx->runtime()->localeCallbacks && cx->runtime()->localeCallbacks->localeToUnicode) {
-        Rooted<Value> v(cx, StringValue(str));
-        bool ok = !!cx->runtime()->localeCallbacks->localeToUnicode(cx, buf, &v);
-        if (ok)
-            args.rval().set(v);
-        js_free(buf);
-        return ok;
-    }
-
-    str = NewStringCopyN<CanGC>(cx, buf, buflen);
-    js_free(buf);
-    if (!str)
-        return false;
-
-    args.rval().setString(str);
-    return true;
-}
-
-static bool
-num_toLocaleString(JSContext* cx, unsigned argc, Value* vp)
-{
-    CallArgs args = CallArgsFromVp(argc, vp);
-    return CallNonGenericMethod<IsNumber, num_toLocaleString_impl>(cx, args);
-}
-#endif /* !EXPOSE_INTL_API */
-
 MOZ_ALWAYS_INLINE bool
 num_valueOf_impl(JSContext* cx, const CallArgs& args)
 {
@@ -1075,11 +940,7 @@ static const JSFunctionSpec number_methods[] = {
     JS_FN(js_toSource_str,       num_toSource,          0, 0),
 #endif
     JS_FN(js_toString_str,       num_toString,          1, 0),
-#if EXPOSE_INTL_API
     JS_SELF_HOSTED_FN(js_toLocaleString_str, "Number_toLocaleString", 0,0),
-#else
-    JS_FN(js_toLocaleString_str, num_toLocaleString,     0,0),
-#endif
     JS_FN(js_valueOf_str,        num_valueOf,           0, 0),
     JS_FN("toFixed",             num_toFixed,           1, 0),
     JS_FN("toExponential",       num_toExponential,     1, 0),
@@ -1130,76 +991,11 @@ js::FIX_FPU()
 #endif
 }
 
-bool
+void
 js::InitRuntimeNumberState(JSRuntime* rt)
 {
     FIX_FPU();
-
-    // XXX If EXPOSE_INTL_API becomes true all the time at some point,
-    //     js::InitRuntimeNumberState is no longer fallible, and we should
-    //     change its return type.
-#if !EXPOSE_INTL_API
-    /* Copy locale-specific separators into the runtime strings. */
-    const char* thousandsSeparator;
-    const char* decimalPoint;
-    const char* grouping;
-#ifdef HAVE_LOCALECONV
-    struct lconv* locale = localeconv();
-    thousandsSeparator = locale->thousands_sep;
-    decimalPoint = locale->decimal_point;
-    grouping = locale->grouping;
-#else
-    thousandsSeparator = getenv("LOCALE_THOUSANDS_SEP");
-    decimalPoint = getenv("LOCALE_DECIMAL_POINT");
-    grouping = getenv("LOCALE_GROUPING");
-#endif
-    if (!thousandsSeparator)
-        thousandsSeparator = "'";
-    if (!decimalPoint)
-        decimalPoint = ".";
-    if (!grouping)
-        grouping = "\3\0";
-
-    /*
-     * We use single malloc to get the memory for all separator and grouping
-     * strings.
-     */
-    size_t thousandsSeparatorSize = strlen(thousandsSeparator) + 1;
-    size_t decimalPointSize = strlen(decimalPoint) + 1;
-    size_t groupingSize = strlen(grouping) + 1;
-
-    char* storage = js_pod_malloc<char>(thousandsSeparatorSize +
-                                        decimalPointSize +
-                                        groupingSize);
-    if (!storage)
-        return false;
-
-    js_memcpy(storage, thousandsSeparator, thousandsSeparatorSize);
-    rt->thousandsSeparator = storage;
-    storage += thousandsSeparatorSize;
-
-    js_memcpy(storage, decimalPoint, decimalPointSize);
-    rt->decimalSeparator = storage;
-    storage += decimalPointSize;
-
-    js_memcpy(storage, grouping, groupingSize);
-    rt->numGrouping = grouping;
-#endif /* !EXPOSE_INTL_API */
-    return true;
-}
-
-#if !EXPOSE_INTL_API
-void
-js::FinishRuntimeNumberState(JSRuntime* rt)
-{
-    /*
-     * The free also releases the memory for decimalSeparator and numGrouping
-     * strings.
-     */
-    char* storage = const_cast<char*>(rt->thousandsSeparator);
-    js_free(storage);
 }
-#endif
 
 JSObject*
 js::InitNumberClass(JSContext* cx, HandleObject obj)
diff --git a/js/src/jsnum.h b/js/src/jsnum.h
index 62b3d617f..8dff45f69 100644
--- a/js/src/jsnum.h
+++ b/js/src/jsnum.h
@@ -34,13 +34,7 @@ namespace js {
 
 class StringBuffer;
 
-extern MOZ_MUST_USE bool
-InitRuntimeNumberState(JSRuntime* rt);
-
-#if !EXPOSE_INTL_API
-extern void
-FinishRuntimeNumberState(JSRuntime* rt);
-#endif
+void InitRuntimeNumberState(JSRuntime* rt);
 
 /* Initialize the Number class, returning its prototype object. */
 extern JSObject*
diff --git a/js/src/jsprototypes.h b/js/src/jsprototypes.h
index f409dce95..dc7cdb85a 100644
--- a/js/src/jsprototypes.h
+++ b/js/src/jsprototypes.h
@@ -37,11 +37,7 @@
 #define TYPED_ARRAY_CLASP(type)     (&TypedArrayObject::classes[Scalar::type])
 #define ERROR_CLASP(type)           (&ErrorObject::classes[type])
 
-#ifdef EXPOSE_INTL_API
 #define IF_INTL(real,imaginary) real
-#else
-#define IF_INTL(real,imaginary) imaginary
-#endif
 
 #ifdef ENABLE_BINARYDATA
 #define IF_BDATA(real,imaginary) real
diff --git a/js/src/jsstr.cpp b/js/src/jsstr.cpp
index 7adeed620..01b407626 100644
--- a/js/src/jsstr.cpp
+++ b/js/src/jsstr.cpp
@@ -36,9 +36,7 @@
 #include "jit/InlinableNatives.h"
 #include "js/Conversions.h"
 #include "js/UniquePtr.h"
-#if ENABLE_INTL_API
 #include "unicode/unorm.h"
-#endif
 #include "vm/GlobalObject.h"
 #include "vm/Interpreter.h"
 #include "vm/Opcodes.h"
@@ -899,38 +897,6 @@ js::str_toLocaleUpperCase(JSContext* cx, unsigned argc, Value* vp)
     return ToUpperCaseHelper(cx, args);
 }
 
-#if !EXPOSE_INTL_API
-bool
-js::str_localeCompare(JSContext* cx, unsigned argc, Value* vp)
-{
-    CallArgs args = CallArgsFromVp(argc, vp);
-    RootedString str(cx, ToStringForStringFunction(cx, args.thisv()));
-    if (!str)
-        return false;
-
-    RootedString thatStr(cx, ToString<CanGC>(cx, args.get(0)));
-    if (!thatStr)
-        return false;
-
-    if (cx->runtime()->localeCallbacks && cx->runtime()->localeCallbacks->localeCompare) {
-        RootedValue result(cx);
-        if (!cx->runtime()->localeCallbacks->localeCompare(cx, str, thatStr, &result))
-            return false;
-
-        args.rval().set(result);
-        return true;
-    }
-
-    int32_t result;
-    if (!CompareStrings(cx, str, thatStr, &result))
-        return false;
-
-    args.rval().setInt32(result);
-    return true;
-}
-#endif
-
-#if EXPOSE_INTL_API
 /* ES6 20140210 draft 21.1.3.12. */
 bool
 js::str_normalize(JSContext* cx, unsigned argc, Value* vp)
@@ -1007,7 +973,6 @@ js::str_normalize(JSContext* cx, unsigned argc, Value* vp)
     args.rval().setString(ns);
     return true;
 }
-#endif
 
 bool
 js::str_charAt(JSContext* cx, unsigned argc, Value* vp)
@@ -2599,15 +2564,9 @@ static const JSFunctionSpec string_methods[] = {
     JS_FN("trimRight",         str_trimRight,         0,0),
     JS_FN("toLocaleLowerCase", str_toLocaleLowerCase, 0,0),
     JS_FN("toLocaleUpperCase", str_toLocaleUpperCase, 0,0),
-#if EXPOSE_INTL_API
     JS_SELF_HOSTED_FN("localeCompare", "String_localeCompare", 1,0),
-#else
-    JS_FN("localeCompare",     str_localeCompare,     1,0),
-#endif
     JS_SELF_HOSTED_FN("repeat", "String_repeat",      1,0),
-#if EXPOSE_INTL_API
     JS_FN("normalize",         str_normalize,         0,0),
-#endif
 
     /* Perl-ish methods (search is actually Python-esque). */
     JS_SELF_HOSTED_FN("match", "String_match",        1,0),
@@ -2918,9 +2877,7 @@ static const JSFunctionSpec string_static_methods[] = {
     JS_SELF_HOSTED_FN("trimRight",       "String_static_trimRight",     1,0),
     JS_SELF_HOSTED_FN("toLocaleLowerCase","String_static_toLocaleLowerCase",1,0),
     JS_SELF_HOSTED_FN("toLocaleUpperCase","String_static_toLocaleUpperCase",1,0),
-#if EXPOSE_INTL_API
     JS_SELF_HOSTED_FN("normalize",       "String_static_normalize",     1,0),
-#endif
     JS_SELF_HOSTED_FN("concat",          "String_static_concat",        2,0),
 
     JS_SELF_HOSTED_FN("localeCompare",   "String_static_localeCompare", 2,0),
diff --git a/js/src/jsstr.h b/js/src/jsstr.h
index 3b92aa21b..118118839 100644
--- a/js/src/jsstr.h
+++ b/js/src/jsstr.h
@@ -9,6 +9,7 @@
 
 #include "mozilla/HashFunctions.h"
 #include "mozilla/PodOperations.h"
+#include "mozilla/TextUtils.h"
 
 #include <stdio.h>
 
@@ -95,7 +96,7 @@ struct JSSubString {
 #define JS7_UNOCT(c)    (JS7_UNDEC(c))
 #define JS7_ISHEX(c)    ((c) < 128 && isxdigit(c))
 #define JS7_UNHEX(c)    (unsigned)(JS7_ISDEC(c) ? (c) - '0' : 10 + tolower(c) - 'a')
-#define JS7_ISLET(c)    ((c) < 128 && isalpha(c))
+#define JS7_ISLET(c)    (mozilla::IsAsciiAlpha(c))
 
 extern size_t
 js_strlen(const char16_t* s);
@@ -377,13 +378,8 @@ str_toLocaleLowerCase(JSContext* cx, unsigned argc, Value* vp);
 extern bool
 str_toLocaleUpperCase(JSContext* cx, unsigned argc, Value* vp);
 
-#if !EXPOSE_INTL_API
-extern bool
-str_localeCompare(JSContext* cx, unsigned argc, Value* vp);
-#else
 extern bool
 str_normalize(JSContext* cx, unsigned argc, Value* vp);
-#endif
 
 extern bool
 str_concat(JSContext* cx, unsigned argc, Value* vp);
diff --git a/js/src/make-source-package.sh b/js/src/make-source-package.sh
index 6e44dd977..e6d3f6df5 100755
--- a/js/src/make-source-package.sh
+++ b/js/src/make-source-package.sh
@@ -151,7 +151,6 @@ case $cmd in
         ${TOPSRCDIR}/memory/moz.build \
         ${TOPSRCDIR}/memory/build \
         ${TOPSRCDIR}/memory/fallible \
-        ${TOPSRCDIR}/memory/jemalloc \
         ${TOPSRCDIR}/memory/mozalloc \
         ${TOPSRCDIR}/memory/mozjemalloc \
         ${tgtpath}/memory
diff --git a/js/src/moz.build b/js/src/moz.build
index 2d4e83db3..a3283b5d6 100644
--- a/js/src/moz.build
+++ b/js/src/moz.build
@@ -645,18 +645,17 @@ else:
 FORCE_STATIC_LIB = True
 STATIC_LIBRARY_NAME = 'js_static'
 
-if CONFIG['ENABLE_INTL_API']:
-    if not CONFIG['MOZ_ICU_DATA_ARCHIVE']:
-        USE_LIBS += [
-            'icu',
-        ]
-    else:
-        # Linking 'icu' will pull in the stubdata library,
-        # which the shell doesn't want, so link the other bits.
-        USE_LIBS += [
-            'icui18n',
-            'icuuc',
-        ]
+if not CONFIG['MOZ_ICU_DATA_ARCHIVE']:
+    USE_LIBS += [
+        'icu',
+    ]
+else:
+    # Linking 'icu' will pull in the stubdata library,
+    # which the shell doesn't want, so link the other bits.
+    USE_LIBS += [
+        'icui18n',
+        'icuuc',
+    ]
 
 USE_LIBS += [
     'nspr',
diff --git a/js/src/old-configure.in b/js/src/old-configure.in
index 1736cc5d4..8abea5956 100644
--- a/js/src/old-configure.in
+++ b/js/src/old-configure.in
@@ -734,12 +734,14 @@ case "$target" in
           dnl VS2012+ defaults to -arch:SSE2. We want to target nothing
           dnl more recent, so set that explicitly here unless another
           dnl target arch has already been set.
+          changequote(,)
           if test -z `echo $CFLAGS | grep -i [-/]arch:` ; then
             CFLAGS="$CFLAGS -arch:SSE2"
-            fi
+          fi
           if test -z `echo $CXXFLAGS | grep -i [-/]arch:` ; then
             CXXFLAGS="$CXXFLAGS -arch:SSE2"
           fi
+          changequote([,])
         fi
         dnl VS2013+ requires -FS when parallel building by make -jN.
         dnl If nothing, compiler sometimes causes C1041 error.
@@ -1534,6 +1536,14 @@ MOZ_ARG_ENABLE_STRING(ui-locale,
 AC_SUBST(MOZ_UI_LOCALE)
 
 dnl ========================================================
+dnl Build the tests?
+dnl ========================================================
+MOZ_ARG_ENABLE_BOOL(tests,
+[  --enable-tests          Build test libraries & programs],
+    ENABLE_TESTS=1,
+    ENABLE_TESTS= )
+
+dnl ========================================================
 dnl =
 dnl = Module specific options
 dnl =
@@ -2091,6 +2101,8 @@ AC_SUBST(MOZ_DEBUG_LDFLAGS)
 AC_SUBST(WARNINGS_AS_ERRORS)
 AC_SUBST(LIBICONV)
 
+AC_SUBST(ENABLE_TESTS)
+
 AC_SUBST(ENABLE_STRIP)
 AC_SUBST(PKG_SKIP_STRIP)
 AC_SUBST(INCREMENTAL_LINKER)
@@ -2244,8 +2256,6 @@ AC_SUBST(JS_LIBRARY_NAME)
 AC_SUBST(JS_CONFIG_MOZ_JS_LIBS)
 AC_SUBST(JS_CONFIG_LIBS)
 
-MOZ_SUBCONFIGURE_JEMALLOC()
-
 # Avoid using obsolete NSPR features
 AC_DEFINE(NO_NSPR_10_SUPPORT)
 
diff --git a/js/src/shell/js.cpp b/js/src/shell/js.cpp
index 8d69ca942..8d144417a 100644
--- a/js/src/shell/js.cpp
+++ b/js/src/shell/js.cpp
@@ -893,7 +893,6 @@ SetPromiseRejectionTrackerCallback(JSContext* cx, unsigned argc, Value* vp)
     return true;
 }
 
-#ifdef ENABLE_INTL_API
 static bool
 AddIntlExtras(JSContext* cx, unsigned argc, Value* vp)
 {
@@ -916,7 +915,6 @@ AddIntlExtras(JSContext* cx, unsigned argc, Value* vp)
     args.rval().setUndefined();
     return true;
 }
-#endif // ENABLE_INTL_API
 
 static bool
 EvalAndPrint(JSContext* cx, const char* bytes, size_t length,
@@ -6140,7 +6138,6 @@ static const JSFunctionSpecWithHelp shell_functions[] = {
 "Sets the callback to be invoked whenever a Promise rejection is unhandled\n"
 "or a previously-unhandled rejection becomes handled."),
 
-#ifdef ENABLE_INTL_API
     JS_FN_HELP("addIntlExtras", AddIntlExtras, 1, 0,
 "addIntlExtras(obj)",
 "Adds various not-yet-standardized Intl functions as properties on the\n"
@@ -6148,7 +6145,6 @@ static const JSFunctionSpecWithHelp shell_functions[] = {
 "functions and their behavior are experimental: don't depend upon them\n"
 "unless you're willing to update your code if these experimental APIs change\n"
 "underneath you."),
-#endif // ENABLE_INTL_API
 
     JS_FS_HELP_END
 };
diff --git a/js/src/shell/moz.build b/js/src/shell/moz.build
index 72ea8145c..e18bad238 100644
--- a/js/src/shell/moz.build
+++ b/js/src/shell/moz.build
@@ -36,7 +36,7 @@ LOCAL_INCLUDES += [
 OS_LIBS += CONFIG['EDITLINE_LIBS']
 OS_LIBS += CONFIG['MOZ_ZLIB_LIBS']
 
-if CONFIG['ENABLE_INTL_API'] and CONFIG['MOZ_ICU_DATA_ARCHIVE']:
+if CONFIG['MOZ_ICU_DATA_ARCHIVE']:
     # The ICU libraries linked into libmozjs will not include the ICU data,
     # so link it directly.
     USE_LIBS += ['icudata']
diff --git a/js/src/threading/windows/ConditionVariable.cpp b/js/src/threading/windows/ConditionVariable.cpp
index 3c75a0f27..92e0249b7 100644
--- a/js/src/threading/windows/ConditionVariable.cpp
+++ b/js/src/threading/windows/ConditionVariable.cpp
@@ -54,8 +54,8 @@ js::ConditionVariable::notify_all()
 void
 js::ConditionVariable::wait(UniqueLock<Mutex>& lock)
 {
-  CRITICAL_SECTION* cs = &lock.lock.platformData()->criticalSection;
-  bool r = SleepConditionVariableCS(&platformData()->cv_, cs, INFINITE);
+  SRWLOCK* srwlock = &lock.lock.platformData()->lock;
+  bool r = SleepConditionVariableSRW(&platformData()->cv_, srwlock, INFINITE, 0);
   MOZ_RELEASE_ASSERT(r);
 }
 
@@ -70,7 +70,7 @@ js::CVStatus
 js::ConditionVariable::wait_for(UniqueLock<Mutex>& lock,
                                 const mozilla::TimeDuration& rel_time)
 {
-  CRITICAL_SECTION* cs = &lock.lock.platformData()->criticalSection;
+  SRWLOCK* srwlock = &lock.lock.platformData()->lock;
 
   // Note that DWORD is unsigned, so we have to be careful to clamp at 0.
   // If rel_time is Forever, then ToMilliseconds is +inf, which evaluates as
@@ -82,7 +82,7 @@ js::ConditionVariable::wait_for(UniqueLock<Mutex>& lock,
                  ? INFINITE
                  : static_cast<DWORD>(msecd);
 
-  BOOL r = SleepConditionVariableCS(&platformData()->cv_, cs, msec);
+  BOOL r = SleepConditionVariableSRW(&platformData()->cv_, srwlock, msec, 0);
   if (r)
     return CVStatus::NoTimeout;
   MOZ_RELEASE_ASSERT(GetLastError() == ERROR_TIMEOUT);
diff --git a/js/src/threading/windows/MutexImpl.cpp b/js/src/threading/windows/MutexImpl.cpp
index 385d1c8de..e838459b5 100644
--- a/js/src/threading/windows/MutexImpl.cpp
+++ b/js/src/threading/windows/MutexImpl.cpp
@@ -13,35 +13,6 @@
 #include "threading/Mutex.h"
 #include "threading/windows/MutexPlatformData.h"
 
-namespace {
-
-// We build with a toolkit that supports WinXP, so we have to probe
-// for modern features at runtime. This is necessary because Vista and
-// later automatically allocate and subsequently leak a debug info
-// object for each critical section that we allocate unless we tell it
-// not to. In order to tell it not to, we need the extra flags field
-// provided by the Ex version of InitializeCriticalSection.
-struct MutexNativeImports
-{
-  using InitializeCriticalSectionExT = BOOL (WINAPI*)(CRITICAL_SECTION*, DWORD, DWORD);
-  InitializeCriticalSectionExT InitializeCriticalSectionEx;
-
-  MutexNativeImports() {
-    HMODULE kernel32_dll = GetModuleHandle("kernel32.dll");
-    MOZ_RELEASE_ASSERT(kernel32_dll != NULL);
-    InitializeCriticalSectionEx = reinterpret_cast<InitializeCriticalSectionExT>(
-      GetProcAddress(kernel32_dll, "InitializeCriticalSectionEx"));
-  }
-
-  bool hasInitializeCriticalSectionEx() const {
-    return InitializeCriticalSectionEx;
-  }
-};
-
-static MutexNativeImports NativeImports;
-
-} // (anonymous namespace)
-
 js::detail::MutexImpl::MutexImpl()
 {
   AutoEnterOOMUnsafeRegion oom;
@@ -49,18 +20,7 @@ js::detail::MutexImpl::MutexImpl()
   if (!platformData_)
     oom.crash("js::Mutex::Mutex");
 
-  // This number was adopted from NSPR.
-  const static DWORD LockSpinCount = 1500;
-  BOOL r;
-  if (NativeImports.hasInitializeCriticalSectionEx()) {
-    r = NativeImports.InitializeCriticalSectionEx(&platformData()->criticalSection,
-                                                  LockSpinCount,
-                                                  CRITICAL_SECTION_NO_DEBUG_INFO);
-  } else {
-    r = InitializeCriticalSectionAndSpinCount(&platformData()->criticalSection,
-                                              LockSpinCount);
-  }
-  MOZ_RELEASE_ASSERT(r);
+  InitializeSRWLock(&platformData()->lock);
 }
 
 js::detail::MutexImpl::~MutexImpl()
@@ -68,18 +28,17 @@ js::detail::MutexImpl::~MutexImpl()
   if (!platformData_)
     return;
 
-  DeleteCriticalSection(&platformData()->criticalSection);
   js_delete(platformData());
 }
 
 void
 js::detail::MutexImpl::lock()
 {
-  EnterCriticalSection(&platformData()->criticalSection);
+  AcquireSRWLockExclusive(&platformData()->lock);
 }
 
 void
 js::detail::MutexImpl::unlock()
 {
-  LeaveCriticalSection(&platformData()->criticalSection);
+  ReleaseSRWLockExclusive(&platformData()->lock);
 }
diff --git a/js/src/threading/windows/MutexPlatformData.h b/js/src/threading/windows/MutexPlatformData.h
index fbe7fc80d..1d741c5d0 100644
--- a/js/src/threading/windows/MutexPlatformData.h
+++ b/js/src/threading/windows/MutexPlatformData.h
@@ -13,7 +13,7 @@
 
 struct js::detail::MutexImpl::PlatformData
 {
-  CRITICAL_SECTION criticalSection;
+  SRWLOCK lock;
 };
 
 #endif // platform_win_MutexPlatformData_h
diff --git a/js/src/vm/DateTime.cpp b/js/src/vm/DateTime.cpp
index e35ad4285..ba3145af2 100644
--- a/js/src/vm/DateTime.cpp
+++ b/js/src/vm/DateTime.cpp
@@ -13,9 +13,7 @@
 #include "jsutil.h"
 
 #include "js/Date.h"
-#if ENABLE_INTL_API
 #include "unicode/timezone.h"
-#endif
 
 using mozilla::Atomic;
 using mozilla::ReleaseAcquire;
@@ -333,7 +331,7 @@ JS::ResetTimeZone()
 {
     js::DateTimeInfo::updateTimeZoneAdjustment();
 
-#if ENABLE_INTL_API && defined(ICU_TZ_HAS_RECREATE_DEFAULT)
+#if defined(ICU_TZ_HAS_RECREATE_DEFAULT)
     TZInfo.acquire();
     TZInfo.status = IcuTimeZoneInfo::NeedsUpdate;
     TZInfo.release();
@@ -343,7 +341,7 @@ JS::ResetTimeZone()
 void
 js::ResyncICUDefaultTimeZone()
 {
-#if ENABLE_INTL_API && defined(ICU_TZ_HAS_RECREATE_DEFAULT)
+#if defined(ICU_TZ_HAS_RECREATE_DEFAULT)
     TZInfo.acquire();
     if (TZInfo.status == IcuTimeZoneInfo::NeedsUpdate) {
         icu::TimeZone::recreateDefault();
diff --git a/js/src/vm/GlobalObject.cpp b/js/src/vm/GlobalObject.cpp
index 280548cd6..c90b6b85f 100644
--- a/js/src/vm/GlobalObject.cpp
+++ b/js/src/vm/GlobalObject.cpp
@@ -17,9 +17,7 @@
 
 #include "builtin/AtomicsObject.h"
 #include "builtin/Eval.h"
-#if EXPOSE_INTL_API
-# include "builtin/Intl.h"
-#endif
+#include "builtin/Intl.h"
 #include "builtin/MapObject.h"
 #include "builtin/ModuleObject.h"
 #include "builtin/Object.h"
diff --git a/js/src/vm/Initialization.cpp b/js/src/vm/Initialization.cpp
index 05cc087cc..39acdf9a8 100644
--- a/js/src/vm/Initialization.cpp
+++ b/js/src/vm/Initialization.cpp
@@ -20,10 +20,8 @@
 #include "jit/ExecutableAllocator.h"
 #include "jit/Ion.h"
 #include "js/Utility.h"
-#if ENABLE_INTL_API
 #include "unicode/uclean.h"
 #include "unicode/utypes.h"
-#endif // ENABLE_INTL_API
 #include "vm/DateTime.h"
 #include "vm/HelperThreads.h"
 #include "vm/Runtime.h"
@@ -113,12 +111,10 @@ JS::detail::InitWithFailureDiagnostic(bool isDebugBuild)
 
     js::DateTimeInfo::init();
 
-#if EXPOSE_INTL_API
     UErrorCode err = U_ZERO_ERROR;
     u_init(&err);
     if (U_FAILURE(err))
         return "u_init() failed";
-#endif // EXPOSE_INTL_API
 
     RETURN_IF_FAIL(js::CreateHelperThreadsState());
     RETURN_IF_FAIL(FutexRuntime::initialize());
@@ -171,9 +167,7 @@ JS_ShutDown(void)
     // to do it only when PRMJ_Now is eventually called.
     PRMJ_NowShutdown();
 
-#if EXPOSE_INTL_API
     u_cleanup();
-#endif // EXPOSE_INTL_API
 
     if (!JSRuntime::hasLiveRuntimes())
         js::jit::ReleaseProcessExecutableMemory();
@@ -188,11 +182,7 @@ JS_SetICUMemoryFunctions(JS_ICUAllocFn allocFn, JS_ICUReallocFn reallocFn, JS_IC
                "must call JS_SetICUMemoryFunctions before any other JSAPI "
                "operation (including JS_Init)");
 
-#if EXPOSE_INTL_API
     UErrorCode status = U_ZERO_ERROR;
     u_setMemoryFunctions(/* context = */ nullptr, allocFn, reallocFn, freeFn, &status);
     return U_SUCCESS(status);
-#else
-    return true;
-#endif
 }
diff --git a/js/src/vm/Runtime.cpp b/js/src/vm/Runtime.cpp
index 0d6a3922c..174e23594 100644
--- a/js/src/vm/Runtime.cpp
+++ b/js/src/vm/Runtime.cpp
@@ -213,11 +213,6 @@ JSRuntime::JSRuntime(JSRuntime* parentRuntime)
     warningReporter(nullptr),
     buildIdOp(nullptr),
     propertyRemovals(0),
-#if !EXPOSE_INTL_API
-    thousandsSeparator(0),
-    decimalSeparator(0),
-    numGrouping(0),
-#endif
     keepAtoms_(0),
     trustedPrincipals_(nullptr),
     beingDestroyed_(false),
@@ -330,8 +325,7 @@ JSRuntime::init(uint32_t maxbytes, uint32_t maxNurseryBytes)
     /* The garbage collector depends on everything before this point being initialized. */
     gcInitialized = true;
 
-    if (!InitRuntimeNumberState(this))
-        return false;
+    InitRuntimeNumberState(this);
 
     JS::ResetTimeZone();
 
@@ -425,10 +419,6 @@ JSRuntime::destroyRuntime()
      */
     FreeScriptData(this, lock);
 
-#if !EXPOSE_INTL_API
-    FinishRuntimeNumberState(this);
-#endif
-
     gc.finish();
     atomsCompartment_ = nullptr;
 
diff --git a/js/src/vm/Runtime.h b/js/src/vm/Runtime.h
index 734543c4e..735adadf2 100644
--- a/js/src/vm/Runtime.h
+++ b/js/src/vm/Runtime.h
@@ -978,13 +978,6 @@ struct JSRuntime : public JS::shadow::Runtime,
      */
     uint32_t            propertyRemovals;
 
-#if !EXPOSE_INTL_API
-    /* Number localization, used by jsnum.cpp. */
-    const char*         thousandsSeparator;
-    const char*         decimalSeparator;
-    const char*         numGrouping;
-#endif
-
   private:
     mozilla::Maybe<js::SharedImmutableStringsCache> sharedImmutableStrings_;
 
diff --git a/js/src/vm/SelfHosting.cpp b/js/src/vm/SelfHosting.cpp
index 9a8ec7679..653807ce8 100644
--- a/js/src/vm/SelfHosting.cpp
+++ b/js/src/vm/SelfHosting.cpp
@@ -2205,11 +2205,7 @@ static const JSFunctionSpec intrinsic_functions[] = {
     JS_FN("std_String_trimRight",                str_trimRight,                0,0),
     JS_FN("std_String_toLocaleLowerCase",        str_toLocaleLowerCase,        0,0),
     JS_FN("std_String_toLocaleUpperCase",        str_toLocaleUpperCase,        0,0),
-#if !EXPOSE_INTL_API
-    JS_FN("std_String_localeCompare",            str_localeCompare,            1,0),
-#else
     JS_FN("std_String_normalize",                str_normalize,                0,0),
-#endif
     JS_FN("std_String_concat",                   str_concat,                   1,0),
     
     JS_FN("std_TypedArray_buffer",               js::TypedArray_bufferGetter,  1,0),
diff --git a/js/src/wasm/AsmJS.cpp b/js/src/wasm/AsmJS.cpp
index b4f41c3d5..7fade24fb 100644
--- a/js/src/wasm/AsmJS.cpp
+++ b/js/src/wasm/AsmJS.cpp
@@ -857,7 +857,7 @@ class NumLit
   private:
     Which which_;
     union {
-        Value scalar_;
+        JS::UninitializedValue scalar_;
         SimdConstant simd_;
     } u;
 
@@ -880,7 +880,7 @@ class NumLit
 
     int32_t toInt32() const {
         MOZ_ASSERT(which_ == Fixnum || which_ == NegativeInt || which_ == BigUnsigned);
-        return u.scalar_.toInt32();
+        return u.scalar_.asValueRef().toInt32();
     }
 
     uint32_t toUint32() const {
@@ -889,17 +889,17 @@ class NumLit
 
     RawF64 toDouble() const {
         MOZ_ASSERT(which_ == Double);
-        return RawF64(u.scalar_.toDouble());
+        return RawF64(u.scalar_.asValueRef().toDouble());
     }
 
     RawF32 toFloat() const {
         MOZ_ASSERT(which_ == Float);
-        return RawF32(float(u.scalar_.toDouble()));
+        return RawF32(float(u.scalar_.asValueRef().toDouble()));
     }
 
     Value scalarValue() const {
         MOZ_ASSERT(which_ != OutOfRangeInt);
-        return u.scalar_;
+        return u.scalar_.asValueRef();
     }
 
     bool isSimd() const
diff --git a/js/xpconnect/shell/moz.build b/js/xpconnect/shell/moz.build
index ecc796f7f..d4f5d55af 100644
--- a/js/xpconnect/shell/moz.build
+++ b/js/xpconnect/shell/moz.build
@@ -35,22 +35,6 @@ if CONFIG['_MSC_VER']:
 if CONFIG['OS_ARCH'] == 'WINNT':
     RCINCLUDE = 'xpcshell.rc'
 
-    if CONFIG['MOZ_SANDBOX']:
-        # For sandbox includes and the include dependencies those have
-        LOCAL_INCLUDES += [
-            '/security/sandbox/chromium',
-            '/security/sandbox/chromium-shim',
-        ]
-
-        USE_LIBS += [
-            'sandbox_s',
-        ]
-
-        DELAYLOAD_DLLS += [
-            'winmm.dll',
-            'user32.dll',
-        ]
-
     DELAYLOAD_DLLS += [
         'xul.dll',
     ]
diff --git a/js/xpconnect/shell/xpcshell.cpp b/js/xpconnect/shell/xpcshell.cpp
index ba979bc69..4eef3f6bf 100644
--- a/js/xpconnect/shell/xpcshell.cpp
+++ b/js/xpconnect/shell/xpcshell.cpp
@@ -22,9 +22,6 @@
 #define XRE_DONT_PROTECT_DLL_LOAD
 #define XRE_WANT_ENVIRON
 #include "nsWindowsWMain.cpp"
-#ifdef MOZ_SANDBOX
-#include "mozilla/sandboxing/SandboxInitialization.h"
-#endif
 #endif
 
 #ifdef MOZ_WIDGET_GTK
@@ -53,13 +50,7 @@ main(int argc, char** argv, char** envp)
     DllBlocklist_Initialize();
 #endif
 
-    XREShellData shellData;
-#if defined(XP_WIN) && defined(MOZ_SANDBOX)
-    shellData.sandboxBrokerServices =
-      mozilla::sandboxing::GetInitializedBrokerServices();
-#endif
-
-    int result = XRE_XPCShellMain(argc, argv, envp, &shellData);
+    int result = XRE_XPCShellMain(argc, argv, envp);
 
 #ifdef XP_MACOSX
     FinishAutoreleasePool();
diff --git a/js/xpconnect/src/XPCJSContext.cpp b/js/xpconnect/src/XPCJSContext.cpp
index f5f6a11bb..8862bca32 100644
--- a/js/xpconnect/src/XPCJSContext.cpp
+++ b/js/xpconnect/src/XPCJSContext.cpp
@@ -59,10 +59,6 @@
 #include "nsIXULRuntime.h"
 #include "nsJSPrincipals.h"
 
-#if defined(MOZ_JEMALLOC4)
-#include "mozmemory.h"
-#endif
-
 #ifdef XP_WIN
 #include <windows.h>
 #endif
@@ -147,18 +143,6 @@ public:
               mActive = false;
           }
       } else {
-#if defined(MOZ_JEMALLOC4)
-          if (mPurge) {
-              /* Jemalloc purges dirty pages regularly during free() when the
-               * ratio of dirty pages compared to active pages is higher than
-               * 1 << lg_dirty_mult. A high ratio can have an impact on
-               * performance, so we use the default ratio of 8, but force a
-               * regular purge of all remaining dirty pages, after cycle
-               * collection. */
-              Telemetry::AutoTimer<Telemetry::MEMORY_FREE_PURGED_PAGES_MS> timer;
-              jemalloc_free_dirty_pages();
-          }
-#endif
           mActive = false;
       }
       return NS_OK;
diff --git a/js/xpconnect/src/XPCShellImpl.cpp b/js/xpconnect/src/XPCShellImpl.cpp
index 45d00d390..a6432856d 100644
--- a/js/xpconnect/src/XPCShellImpl.cpp
+++ b/js/xpconnect/src/XPCShellImpl.cpp
@@ -44,9 +44,6 @@
 #ifdef XP_WIN
 #include "mozilla/widget/AudioSession.h"
 #include <windows.h>
-#if defined(MOZ_SANDBOX)
-#include "SandboxBroker.h"
-#endif
 #endif
 
 // all this crap is needed to do the interactive shell stuff
@@ -1235,11 +1232,8 @@ GetCurrentWorkingDirectory(nsAString& workingDirectory)
 static JSSecurityCallbacks shellSecurityCallbacks;
 
 int
-XRE_XPCShellMain(int argc, char** argv, char** envp,
-                 const XREShellData* aShellData)
+XRE_XPCShellMain(int argc, char** argv, char** envp)
 {
-    MOZ_ASSERT(aShellData);
-
     JSContext* cx;
     int result = 0;
     nsresult rv;
@@ -1484,16 +1478,6 @@ XRE_XPCShellMain(int argc, char** argv, char** envp,
         // Plugin may require audio session if installed plugin can initialize
         // asynchronized.
         AutoAudioSession audioSession;
-
-#if defined(MOZ_SANDBOX)
-        // Required for sandboxed child processes.
-        if (aShellData->sandboxBrokerServices) {
-          SandboxBroker::Initialize(aShellData->sandboxBrokerServices);
-        } else {
-          NS_WARNING("Failed to initialize broker services, sandboxed "
-                     "processes will fail to start.");
-        }
-#endif
 #endif
 
         {
diff --git a/js/xpconnect/src/XPCWrappedNative.cpp b/js/xpconnect/src/XPCWrappedNative.cpp
index acf92f3c3..a12e36baa 100644
--- a/js/xpconnect/src/XPCWrappedNative.cpp
+++ b/js/xpconnect/src/XPCWrappedNative.cpp
@@ -1785,9 +1785,12 @@ CallMethodHelper::ConvertIndependentParam(uint8_t i)
     // indirectly, regardless of in/out-ness.
     if (type_tag == nsXPTType::T_JSVAL) {
         // Root the value.
-        dp->val.j.setUndefined();
-        if (!js::AddRawValueRoot(mCallContext, &dp->val.j, "XPCWrappedNative::CallMethod param"))
+        dp->val.j.asValueRef().setUndefined();
+        if (!js::AddRawValueRoot(mCallContext, &dp->val.j.asValueRef(),
+                                 "XPCWrappedNative::CallMethod param"))
+        {
             return false;
+        }
     }
 
     // Flag cleanup for anything that isn't self-contained.