Revert of [intrinsic] Drop the %_ValueOf intrinsic.

src/debug/mirrors.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.
 
 (function(global, utils) {
 "use strict";
 
 // ----------------------------------------------------------------------------
 // Imports
 
 var ErrorToString;
 var GlobalArray = global.Array;
 var IsNaN = global.isNaN;
 var JSONStringify = global.JSON.stringify;
 var MakeError;
 var MapEntries;
 var MapIteratorNext;
 var promiseStateSymbol = utils.ImportNow("promise_state_symbol");
 var promiseResultSymbol = utils.ImportNow("promise_result_symbol");
 var SetIteratorNext;
 var SetValues;
+var SymbolToString;
 
 utils.Import(function(from) {
   ErrorToString = from.ErrorToString;
   MakeError = from.MakeError;
   MapEntries = from.MapEntries;
   MapIteratorNext = from.MapIteratorNext;
   SetIteratorNext = from.SetIteratorNext;
   SetValues = from.SetValues;
+  SymbolToString = from.SymbolToString;
 });
 
 // ----------------------------------------------------------------------------
 
 // Mirror hierarchy:
 // - Mirror
 //   - ValueMirror
 //     - UndefinedMirror
 //     - NullMirror
 //     - BooleanMirror
@@ skipping 637 matching lines @@
  * @constructor
  * @extends Mirror
  */
 function SymbolMirror(value) {
   %_Call(ValueMirror, this, MirrorType.SYMBOL_TYPE, value);
 }
 inherits(SymbolMirror, ValueMirror);
 
 
 SymbolMirror.prototype.description = function() {
-  return %SymbolDescription(%ValueOf(this.value_));
+  return %SymbolDescription(%_ValueOf(this.value_));
 }
 
 
 SymbolMirror.prototype.toText = function() {
-  return %SymbolDescriptiveString(%ValueOf(this.value_));
+  return %_Call(SymbolToString, this.value_);
 }
 
 
 /**
  * Mirror object for objects.
  * @param {object} value The object reflected by this mirror
  * @param {boolean} transient indicate whether this object is transient with a
  *    transient handle
  * @constructor
  * @extends ValueMirror
@@ skipping 2342 matching lines @@
 // Functions needed by the debugger runtime.
 utils.InstallFunctions(utils, DONT_ENUM, [
   "ClearMirrorCache", ClearMirrorCache
 ]);
 
 // Export to debug.js
 utils.Export(function(to) {
   to.MirrorType = MirrorType;
 });
 })