Call JS functions via native context instead of js builtins object.

src/regexp.js

 // Copyright 2012 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.
 
 var $regexpLastMatchInfoOverride;
 var harmony_regexps = false;
 var harmony_unicode_regexps = false;
 
 (function(global, utils) {
 
 %CheckIsBootstrapping();
 
 // -------------------------------------------------------------------
 // Imports
 
 var GlobalRegExp = global.RegExp;
 var InternalPackedArray = utils.InternalPackedArray;
+var ToNumber;
 
 utils.Import(function(from) {
   ToNumber = from.ToNumber;
 });
 
 // -------------------------------------------------------------------
 
 // Property of the builtins object for recording the result of the last
 // regexp match.  The property RegExpLastMatchInfo includes the matchIndices
 // array of the last successful regexp match (an array of start/end index
@@ skipping 420 matching lines @@
 // Exports
 
 utils.Export(function(to) {
   to.RegExpExec = DoRegExpExec;
   to.RegExpExecNoTests = RegExpExecNoTests;
   to.RegExpLastMatchInfo = RegExpLastMatchInfo;
   to.RegExpTest = RegExpTest;
 });
 
 })