[stubs] Unify (and optimize) implementation of ToObject.

src/date.js

 // Copyright 2006-2008 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 $createDate;
 
 // -------------------------------------------------------------------
 
 (function(global, utils) {
 
@@ skipping 757 matching lines @@
       '-' + PadInt(UTC_DAY(this), 2) +
       'T' + PadInt(UTC_HOUR(this), 2) +
       ':' + PadInt(UTC_MIN(this), 2) +
       ':' + PadInt(UTC_SEC(this), 2) +
       '.' + PadInt(UTC_MS(this), 3) +
       'Z';
 }
 
 
 function DateToJSON(key) {
-  var o = $toObject(this);
+  var o = TO_OBJECT(this);
   var tv = $defaultNumber(o);
   if (IS_NUMBER(tv) && !NUMBER_IS_FINITE(tv)) {
     return null;
   }
   return o.toISOString();
 }
 
 
 var date_cache_version_holder;
 var date_cache_version = NAN;
@@ skipping 88 matching lines @@
   "getYear", DateGetYear,
   "setYear", DateSetYear,
   "toISOString", DateToISOString,
   "toJSON", DateToJSON
 ]);
 
 // Expose to the global scope.
 $createDate = CreateDate;
 
 })