[Intl] fix Intl.ListFormat / RelativeTimeFormat subclassing bug

Bug: v8:8030, v8:8031
Cq-Include-Trybots: luci.v8.try:v8_linux_noi18n_rel_ng
Change-Id: Iaac58cc3a692ea9d7c986b24414403b57d00b904
Reviewed-on: https://chromium-review.googlesource.com/1180084Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
Commit-Queue: Frank Tang <ftang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#55322}

src/objects.cc

@@ -13082,7 +13082,9 @@ bool CanSubclassHaveInobjectProperties(InstanceType instance_type) {
     case JS_GENERATOR_OBJECT_TYPE:
 #ifdef V8_INTL_SUPPORT
     case JS_INTL_COLLATOR_TYPE:
+    case JS_INTL_LIST_FORMAT_TYPE:
     case JS_INTL_PLURAL_RULES_TYPE:
+    case JS_INTL_RELATIVE_TIME_FORMAT_TYPE:
 #endif
     case JS_ASYNC_GENERATOR_OBJECT_TYPE:
     case JS_MAP_TYPE:

test/intl/regress-8030.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
+
+var locales = ["tlh", "id", "en"];
+var referenceRelativeTimeFormat = new Intl.RelativeTimeFormat(locales);
+var referenceFormatted = referenceRelativeTimeFormat.format(3, "day");
+
+class MyFormat extends Intl.RelativeTimeFormat {
+  constructor(locales, options) {
+    super(locales, options);
+    // could initialize MyRelativeTimeFormat properties
+  }
+  // could add methods to MyRelativeTimeFormat.prototype
+}
+
+var format = new MyFormat(locales);
+var actual = format.format(3, "day");
+assertEquals(actual, referenceFormatted);

test/intl/regress-8031.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
+
+var locales = ["tlh", "id", "en"];
+var input = ["a", "b", "c"];
+var referenceListFormat = new Intl.ListFormat(locales);
+var referenceFormatted = referenceListFormat.format(input);
+
+class MyFormat extends Intl.ListFormat {
+  constructor(locales, options) {
+    super(locales, options);
+    // could initialize MyListFormat properties
+  }
+  // could add methods to MyListFormat.prototype
+}
+
+var format = new MyFormat(locales);
+var actual = format.format(input);
+assertEquals(actual, referenceFormatted);