Expose Array.prototype.values behind a flag and stage it

BUG=v8:4247
LOG=y

Review URL: https://codereview.chromium.org/1781573003

Cr-Commit-Position: refs/heads/master@{#34640}

src/bootstrapper.cc

@@ -2527,6 +2527,26 @@ void Genesis::InitializeGlobal_harmony_proxies() {
   InstallFunction(global, name, proxy_function, factory->Object_string());
 }
 
+void Genesis::InitializeGlobal_harmony_array_prototype_values() {
+  if (!FLAG_harmony_array_prototype_values) return;
+  Handle<JSFunction> array_constructor(native_context()->array_function());
+  Handle<JSObject> array_prototype(
+      JSObject::cast(array_constructor->instance_prototype()));
+  Handle<Object> values_iterator =
+      JSObject::GetProperty(array_prototype, factory()->iterator_symbol())
+          .ToHandleChecked();
+  DCHECK(values_iterator->IsJSFunction());
+  JSObject::AddProperty(array_prototype, factory()->values_string(),
+                        values_iterator, DONT_ENUM);
+
+  Handle<Object> unscopables =
+      JSObject::GetProperty(array_prototype, factory()->unscopables_symbol())
+          .ToHandleChecked();
+  DCHECK(unscopables->IsJSObject());
+  JSObject::AddProperty(Handle<JSObject>::cast(unscopables),
+                        factory()->values_string(), factory()->true_value(),
+                        NONE);
+}
 
 Handle<JSFunction> Genesis::InstallArrayBuffer(Handle<JSObject> target,
                                                const char* name) {
@@ -2967,6 +2987,7 @@ bool Genesis::InstallExperimentalNatives() {
   static const char* harmony_object_values_entries_natives[] = {nullptr};
   static const char* harmony_object_own_property_descriptors_natives[] = {
       nullptr};
+  static const char* harmony_array_prototype_values_natives[] = {nullptr};
 
   for (int i = ExperimentalNatives::GetDebuggerCount();
        i < ExperimentalNatives::GetBuiltinsCount(); i++) {

src/flag-definitions.h

@@ -218,6 +218,7 @@ DEFINE_IMPLICATION(es_staging, harmony_tailcalls)
 
 // Features that are complete (but still behind --harmony/es-staging flag).
 #define HARMONY_STAGED(V)                                                    \
+  V(harmony_array_prototype_values, "harmony Array.prototype.values")        \
   V(harmony_regexp_lookbehind, "harmony regexp lookbehind")                  \
   V(harmony_instanceof, "harmony instanceof support")                        \
   V(harmony_object_values_entries, "harmony Object.values / Object.entries") \

test/mjsunit/es6/array-prototype-values.js

+// Copyright 2016 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-array-prototype-values
+
+// Functionality of the values iterator is tested elsewhere; this test
+// merely verifies that the 'values' property is set up correctly.
+var valuesDesc = Object.getOwnPropertyDescriptor(Array.prototype, 'values');
+assertEquals('object', typeof valuesDesc);
+assertSame(Array.prototype[Symbol.iterator], valuesDesc.value);
+assertTrue(valuesDesc.configurable);
+assertTrue(valuesDesc.writable);
+assertFalse(valuesDesc.enumerable);
+assertTrue(Array.prototype[Symbol.unscopables].values);

test/test262/test262.status

@@ -59,18 +59,6 @@
   'language/computed-property-names/class/static/method-symbol': [FAIL, FAIL_SLOPPY],
   'language/computed-property-names/class/static/method-string': [FAIL, FAIL_SLOPPY],
 
-  # We do not expose Array.prototype.values
-  # https://code.google.com/p/v8/issues/detail?id=4247
-  'built-ins/Array/prototype/Symbol.iterator': [FAIL],
-  'built-ins/Array/prototype/values/returns-iterator': [FAIL],
-  'built-ins/Array/prototype/values/returns-iterator-from-object': [FAIL],
-  'built-ins/Array/prototype/values/prop-desc': [FAIL],
-  'built-ins/Array/prototype/values/name': [FAIL],
-  'built-ins/Array/prototype/values/length': [FAIL],
-  'built-ins/Array/prototype/values/iteration': [FAIL],
-  'built-ins/Array/prototype/values/iteration-mutable': [FAIL],
-  'built-ins/Array/prototype/Symbol.unscopables/value': [FAIL],
-
   # https://code.google.com/p/v8/issues/detail?id=4248
   'language/expressions/compound-assignment/S11.13.2_A5.*': [FAIL],
   'language/expressions/compound-assignment/S11.13.2_A6.*': [FAIL],