Fix toLocaleString-related breakage on buildbot.

src/array.js

 // Copyright 2006-2008 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 153 matching lines @@
 
 function ConvertToLocaleString(e) {
   if (typeof(e) === 'string') return e;
   if (e == null) return '';
   else {
     // e_obj's toLocaleString might be overwritten, check if it is a function.
     // Call ToString if toLocaleString is not a function.
     // See issue 877615.
     var e_obj = ToObject(e);
     if (IS_FUNCTION(e_obj.toLocaleString))
-      return e_obj.toLocaleString();
+      return ToString(e_obj.toLocaleString());
     else
       return ToString(e);
   }
 }
 
 
 // This function implements the optimized splice implementation that can use
 // special array operations to handle sparse arrays in a sensible fashion.
 function SmartSlice(array, start_i, del_count, len, deleted_elements) {
   // Move deleted elements to a new array (the return value from splice).
@@ skipping 958 matching lines @@
     ArrayIndexOf: 1,
     ArrayLastIndexOf: 1,
     ArrayPush: 1,
     ArrayReduce: 1,
     ArrayReduceRight: 1
   });
 }
 
 
 SetupArray();