Wrap messages implementation in a function.

src/mirror-debugger.js

 // Copyright 2006-2012 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.
 "use strict";
 
 // Handle id counters.
 var next_handle_ = 0;
 var next_transient_handle_ = -1;
 
 // Mirror cache.
@@ skipping 1296 matching lines @@
  */
 ErrorMirror.prototype.message = function() {
   return this.value_.message;
 };
 
 
 ErrorMirror.prototype.toText = function() {
   // Use the same text representation as in messages.js.
   var text;
   try {
-    text = %_CallFunction(this.value_, builtins.ErrorToString);
+    text = %_CallFunction(this.value_, builtins.$errorToString);
   } catch (e) {
     text = '#<Error>';
   }
   return text;
 };
 
 
 /**
  * Mirror object for a Promise object.
  * @param {Object} value The Promise object
@@ skipping 1734 matching lines @@
   }
   if (!NUMBER_IS_FINITE(value)) {
     if (value > 0) {
       return 'Infinity';
     } else {
       return '-Infinity';
     }
   }
   return value;
 }