[builtins] Unify the String constructor.

src/symbol.js

 // Copyright 2013 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";
 
 %CheckIsBootstrapping();
 
@@ skipping 35 matching lines @@
   }
   return %_ValueOf(this);
 }
 
 
 function SymbolToString() {
   if (!(IS_SYMBOL(this) || IS_SYMBOL_WRAPPER(this))) {
     throw MakeTypeError(kIncompatibleMethodReceiver,
                         "Symbol.prototype.toString", this);
   }
-  var description = %SymbolDescription(%_ValueOf(this));
-  return "Symbol(" + (IS_UNDEFINED(description) ? "" : description) + ")";
+  return %SymbolDescriptiveString(%_ValueOf(this));
 }
 
 
 function SymbolValueOf() {
   if (!(IS_SYMBOL(this) || IS_SYMBOL_WRAPPER(this))) {
     throw MakeTypeError(kIncompatibleMethodReceiver,
                         "Symbol.prototype.valueOf", this);
   }
   return %_ValueOf(this);
 }
@@ skipping 68 matching lines @@
 ]);
 
 // -------------------------------------------------------------------
 // Exports
 
 utils.Export(function(to) {
   to.SymbolToString = SymbolToString;
 })
 
 })