Add remaining @@toStringTag symbols to builtins

test/mjsunit/es6/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.
 
-// Flags: --allow-natives-syntax
+// Flags: --allow-natives-syntax --harmony-tostring
 
 
 (function TestSetIterator() {
   var s = new Set;
   var iter = s.values();
   assertEquals('Set Iterator', %_ClassOf(iter));
 
   var SetIteratorPrototype = iter.__proto__;
   assertFalse(SetIteratorPrototype.hasOwnProperty('constructor'));
   assertEquals(SetIteratorPrototype.__proto__, Object.prototype);
 
   var propertyNames = Object.getOwnPropertyNames(SetIteratorPrototype);
   assertArrayEquals(['next'], propertyNames);
 
   assertEquals(new Set().values().__proto__, SetIteratorPrototype);
   assertEquals(new Set().entries().__proto__, SetIteratorPrototype);
+
+  assertEquals("[object Set Iterator]",
+      Object.prototype.toString.call(iter));
+  assertEquals("Set Iterator", SetIteratorPrototype[Symbol.toStringTag]);
+  var desc = Object.getOwnPropertyDescriptor(
+      SetIteratorPrototype, Symbol.toStringTag);
+  assertTrue(desc.configurable);
+  assertFalse(desc.writable);
+  assertEquals("Set Iterator", desc.value);
 })();
 
 
 (function TestSetIteratorValues() {
   var s = new Set;
   s.add(1);
   s.add(2);
   s.add(3);
   var iter = s.values();
 
@@ skipping 81 matching lines @@
   var MapIteratorPrototype = iter.__proto__;
   assertFalse(MapIteratorPrototype.hasOwnProperty('constructor'));
   assertEquals(MapIteratorPrototype.__proto__, Object.prototype);
 
   var propertyNames = Object.getOwnPropertyNames(MapIteratorPrototype);
   assertArrayEquals(['next'], propertyNames);
 
   assertEquals(new Map().values().__proto__, MapIteratorPrototype);
   assertEquals(new Map().keys().__proto__, MapIteratorPrototype);
   assertEquals(new Map().entries().__proto__, MapIteratorPrototype);
+
+  assertEquals("[object Map Iterator]",
+      Object.prototype.toString.call(iter));
+  assertEquals("Map Iterator", MapIteratorPrototype[Symbol.toStringTag]);
+  var desc = Object.getOwnPropertyDescriptor(
+      MapIteratorPrototype, Symbol.toStringTag);
+  assertTrue(desc.configurable);
+  assertFalse(desc.writable);
+  assertEquals("Map Iterator", desc.value);
 })();
 
 
 (function TestMapIteratorValues() {
   var m = new Map;
   m.set(1, 11);
   m.set(2, 22);
   m.set(3, 33);
   var iter = m.values();
 
@@ skipping 58 matching lines @@
 
 (function TestMapIteratorSymbol() {
   assertEquals(Map.prototype[Symbol.iterator], Map.prototype.entries);
   assertTrue(Map.prototype.hasOwnProperty(Symbol.iterator));
   assertFalse(Map.prototype.propertyIsEnumerable(Symbol.iterator));
 
   var iter = new Map().values();
   assertEquals(iter, iter[Symbol.iterator]());
   assertEquals(iter[Symbol.iterator].name, '[Symbol.iterator]');
 })();