Move more builtin files to strict mode.

src/i18n.js

 // Copyright 2013 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.
-// limitations under the License.
+
+"use strict";
 
 // ECMAScript 402 API implementation.
 
 /**
  * Intl object is a single object that has some named properties,
  * all of which are constructors.
  */
 $Object.defineProperty(global, "Intl", { enumerable: false, value: (function() {
 
-'use strict';
-
 var Intl = {};
 
 var undefined = global.undefined;
 
 var AVAILABLE_SERVICES = ['collator',
                           'numberformat',
                           'dateformat',
                           'breakiterator'];
 
 var NORMALIZATION_FORMS = ['NFC',
@@ skipping 2073 matching lines @@
   writable: true,
   configurable: true,
   enumerable: false
 });
 %FunctionSetName($Date.prototype.toLocaleTimeString, 'toLocaleTimeString');
 %FunctionRemovePrototype($Date.prototype.toLocaleTimeString);
 %SetNativeFlag($Date.prototype.toLocaleTimeString);
 
 return Intl;
 }())});