Enable ES6 iteration by default

test/mjsunit/es6/typed-array-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-iteration
-
 
 var constructors = [Uint8Array, Int8Array,
                     Uint16Array, Int16Array,
                     Uint32Array, Int32Array,
                     Float32Array, Float64Array,
                     Uint8ClampedArray];
 
 function TestTypedArrayPrototype(constructor) {
   assertTrue(constructor.prototype.hasOwnProperty('entries'));
   assertTrue(constructor.prototype.hasOwnProperty('values'));
@@ skipping 15 matching lines @@
 
 function TestTypedArrayValues(constructor) {
   var array = [1, 2, 3];
   var i = 0;
   for (var value of new constructor(array)) {
     assertEquals(array[i++], value);
   }
   assertEquals(i, array.length);
 }
 constructors.forEach(TestTypedArrayValues);