[Intl] add supportedLocales for Intl.ListFormat

Bug: v8:7871
Cq-Include-Trybots: luci.v8.try:v8_linux_noi18n_rel_ng
Change-Id: Icabd067f4074169230f21a574aedecf30c5049e4
Reviewed-on: https://chromium-review.googlesource.com/1195077
Commit-Queue: Frank Tang <ftang@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#55502}

src/bootstrapper.cc

@@ -4653,6 +4653,9 @@ void Genesis::InitializeGlobal_harmony_intl_list_format() {
   list_format_fun->shared()->set_length(0);
   list_format_fun->shared()->DontAdaptArguments();
 
+  SimpleInstallFunction(isolate(), list_format_fun, "supportedLocalesOf",
+                        Builtins::kListFormatSupportedLocalesOf, 1, false);
+
   // Setup %ListFormatPrototype%.
   Handle<JSObject> prototype(
       JSObject::cast(list_format_fun->instance_prototype()), isolate());

src/builtins/builtins-definitions.h

@@ -1353,6 +1353,8 @@ namespace internal {
   /* ecma402 #sec-intl-list-format.prototype.formattoparts */          \
   TFJ(ListFormatPrototypeFormatToParts,                                \
       SharedFunctionInfo::kDontAdaptArgumentsSentinel)                 \
+  /* ecma402 #sec-intl.ListFormat.supportedlocalesof */                \
+  CPP(ListFormatSupportedLocalesOf)                                    \
   /* ecma402 #sec-intl-locale-constructor */                           \
   CPP(LocaleConstructor)                                               \
   CPP(LocalePrototypeLanguage)                                         \

src/builtins/builtins-intl.cc

@@ -744,6 +744,12 @@ BUILTIN(ListFormatPrototypeResolvedOptions) {
   return *JSListFormat::ResolvedOptions(isolate, format_holder);
 }
 
+BUILTIN(ListFormatSupportedLocalesOf) {
+  HandleScope scope(isolate);
+  RETURN_RESULT_OR_FAILURE(
+      isolate, SupportedLocalesOfCommon(isolate, "listformat", args));
+}
+
 namespace {
 
 MaybeHandle<JSLocale> CreateLocale(Isolate* isolate,

test/intl/list-format/supported-locale.js

+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --harmony-intl-list-format
+assertEquals(typeof Intl.ListFormat.supportedLocalesOf, "function",
+             "Intl.ListFormat.supportedLocalesOf should be a function");
+
+var undef = Intl.ListFormat.supportedLocalesOf();
+assertEquals([], undef);
+
+var empty = Intl.ListFormat.supportedLocalesOf([]);
+assertEquals([], empty);
+
+var strLocale = Intl.ListFormat.supportedLocalesOf('sr');
+assertEquals('sr', strLocale[0]);
+
+var multiLocale = ['sr-Thai-RS', 'de', 'zh-CN'];
+assertEquals(multiLocale, Intl.ListFormat.supportedLocalesOf(multiLocale));

test/intl/relative-time-format/supported-locale.js

+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --harmony-intl-relative-time-format
+assertEquals(typeof Intl.RelativeTimeFormat.supportedLocalesOf, "function",
+             "Intl.RelativeTimeFormat.supportedLocalesOf should be a function");
+
+var undef = Intl.RelativeTimeFormat.supportedLocalesOf();
+assertEquals([], undef);
+
+var empty = Intl.RelativeTimeFormat.supportedLocalesOf([]);
+assertEquals([], empty);
+
+var strLocale = Intl.RelativeTimeFormat.supportedLocalesOf('sr');
+assertEquals('sr', strLocale[0]);
+
+var multiLocale = ['sr-Thai-RS', 'de', 'zh-CN'];
+assertEquals(multiLocale, Intl.RelativeTimeFormat.supportedLocalesOf(multiLocale));