Enable ES6 Map and Set by default

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: --harmony-collections --allow-natives-syntax
+// Flags: --allow-natives-syntax
 
 
 (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);
@@ skipping 175 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]');
 })();