make Intl non-enumerable

src/extensions/i18n/header.js

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 16 matching lines @@
 // limitations under the License.
 
 // ECMAScript 402 API implementation is broken into separate files for
 // each service. The build system combines them together into one
 // Intl namespace.
 
 /**
  * Intl object is a single object that has some named properties,
  * all of which are constructors.
  */
-var Intl = (function() {
+Object.defineProperty(this, "Intl", { enumerable: false, value: (function() {
 
 'use strict';
 
 var Intl = {};