Enable ES6 iteration by default

src/unscopables.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.
 
 'use strict';
 
 // This file relies on the fact that the following declaration has been made.
 // var $Array = global.Array;
 // var $Symbol = global.Symbol;
 
-function ExtendSymbol() {
+function UnscopablesExtendSymbol() {
   %CheckIsBootstrapping();
   InstallConstants($Symbol, $Array(
     "unscopables", symbolUnscopables
   ));
 }
 
-ExtendSymbol();
+UnscopablesExtendSymbol();
 
 
 var arrayUnscopables = {
   __proto__: null,
   copyWithin: true,
   entries: true,
   fill: true,
   find: true,
   findIndex: true,
   keys: true,
   values: true,
 };
 
 
-function ExtendArrayPrototype() {
+function UnscopablesExtendArrayPrototype() {
   %CheckIsBootstrapping();
   %AddNamedProperty($Array.prototype, symbolUnscopables, arrayUnscopables,
                     DONT_ENUM | READ_ONLY);
 }
 
-ExtendArrayPrototype();
+UnscopablesExtendArrayPrototype();