[es6] Iterators and generators should "extend" %IteratorPrototype%

src/collection-iterator.js

 // Copyright 2014 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.
 
 var $mapEntries;
 var $mapIteratorNext;
 var $setIteratorNext;
 var $setValues;
 
 (function(global, shared, exports) {
 
 "use strict";
 
 %CheckIsBootstrapping();
 
 var GlobalMap = global.Map;
-var GlobalObject = global.Object;
 var GlobalSet = global.Set;
 
 // -------------------------------------------------------------------
 
 function SetIteratorConstructor(set, kind) {
   %SetIteratorInitialize(this, set, kind);
 }
 
 
 function SetIteratorNextJS() {
@@ skipping 14 matching lines @@
       break;
     case ITERATOR_KIND_ENTRIES:
       value_array[1] = value_array[0];
       break;
   }
 
   return entry;
 }
 
 
-function SetIteratorSymbolIterator() {
-  return this;
-}
-
-
 function SetEntries() {
   if (!IS_SET(this)) {
     throw MakeTypeError(kIncompatibleMethodReceiver,
                         'Set.prototype.entries', this);
   }
   return new SetIterator(this, ITERATOR_KIND_ENTRIES);
 }
 
 
 function SetValues() {
   if (!IS_SET(this)) {
     throw MakeTypeError(kIncompatibleMethodReceiver,
                         'Set.prototype.values', this);
   }
   return new SetIterator(this, ITERATOR_KIND_VALUES);
 }
 
 // -------------------------------------------------------------------
 
 %SetCode(SetIterator, SetIteratorConstructor);
-%FunctionSetPrototype(SetIterator, new GlobalObject());
+%FunctionSetPrototype(SetIterator, {__proto__: $iteratorPrototype});
 %FunctionSetInstanceClassName(SetIterator, 'Set Iterator');
 $installFunctions(SetIterator.prototype, DONT_ENUM, [
   'next', SetIteratorNextJS
 ]);
 
-$setFunctionName(SetIteratorSymbolIterator, symbolIterator);
-%AddNamedProperty(SetIterator.prototype, symbolIterator,
-    SetIteratorSymbolIterator, DONT_ENUM);
 %AddNamedProperty(SetIterator.prototype, symbolToStringTag,
     "Set Iterator", READ_ONLY | DONT_ENUM);
 
 $installFunctions(GlobalSet.prototype, DONT_ENUM, [
   'entries', SetEntries,
   'keys', SetValues,
   'values', SetValues
 ]);
 
 %AddNamedProperty(GlobalSet.prototype, symbolIterator, SetValues, DONT_ENUM);
 
 $setIteratorNext = SetIteratorNextJS;
 $setValues = SetValues;
 
 // -------------------------------------------------------------------
 
 function MapIteratorConstructor(map, kind) {
   %MapIteratorInitialize(this, map, kind);
 }
 
 
-function MapIteratorSymbolIterator() {
-  return this;
-}
-
-
 function MapIteratorNextJS() {
   if (!IS_MAP_ITERATOR(this)) {
     throw MakeTypeError(kIncompatibleMethodReceiver,
                         'Map Iterator.prototype.next', this);
   }
 
   var value_array = [UNDEFINED, UNDEFINED];
   var entry = {value: value_array, done: false};
   switch (%MapIteratorNext(this, value_array)) {
     case 0:
@@ skipping 35 matching lines @@
   if (!IS_MAP(this)) {
     throw MakeTypeError(kIncompatibleMethodReceiver,
                         'Map.prototype.values', this);
   }
   return new MapIterator(this, ITERATOR_KIND_VALUES);
 }
 
 // -------------------------------------------------------------------
 
 %SetCode(MapIterator, MapIteratorConstructor);
-%FunctionSetPrototype(MapIterator, new GlobalObject());
+%FunctionSetPrototype(MapIterator, {__proto__: $iteratorPrototype});
 %FunctionSetInstanceClassName(MapIterator, 'Map Iterator');
 $installFunctions(MapIterator.prototype, DONT_ENUM, [
   'next', MapIteratorNextJS
 ]);
 
-$setFunctionName(MapIteratorSymbolIterator, symbolIterator);
-%AddNamedProperty(MapIterator.prototype, symbolIterator,
-    MapIteratorSymbolIterator, DONT_ENUM);
 %AddNamedProperty(MapIterator.prototype, symbolToStringTag,
     "Map Iterator", READ_ONLY | DONT_ENUM);
 
 
 $installFunctions(GlobalMap.prototype, DONT_ENUM, [
   'entries', MapEntries,
   'keys', MapKeys,
   'values', MapValues
 ]);
 
 %AddNamedProperty(GlobalMap.prototype, symbolIterator, MapEntries, DONT_ENUM);
 
 $mapEntries = MapEntries;
 $mapIteratorNext = MapIteratorNextJS;
 
 })