This change removes the %AddProperty native JavaScript function from V8....

src/messages.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 145 matching lines @@
   e.type = type;
   e.arguments = args;
   return e;
 }
 
 
 /**
  * Setup the Script function and constructor.
  */
 %FunctionSetInstanceClassName(Script, 'Script');
-%AddProperty(Script.prototype, 'constructor', Script, DONT_ENUM);
+%SetProperty(Script.prototype, 'constructor', Script, DONT_ENUM);
 %SetCode(Script, function(x) {
   // Script objects can only be created by the VM.
   throw new $Error("Not supported");
 });
 
 
 // Helper functions; called from the runtime system.
 function FormatMessage(message) {
   var format = kMessages[message.type];
   if (!format) return "<unknown message " + message.type + ">";
@@ skipping 449 matching lines @@
 // Error implementation
 
 function DefineError(f) {
   // Store the error function in both the global object
   // and the runtime object. The function is fetched
   // from the runtime object when throwing errors from
   // within the runtime system to avoid strange side
   // effects when overwriting the error functions from
   // user code.
   var name = f.name;
-  %AddProperty(global, name, f, DONT_ENUM);
+  %SetProperty(global, name, f, DONT_ENUM);
   this['$' + name] = f;
   // Configure the error function.
   // prototype of 'Error' must be as default: new Object().
   if (name != 'Error') %FunctionSetPrototype(f, new $Error());
   %FunctionSetInstanceClassName(f, 'Error');
   f.prototype.name = name;
   f.prototype.constructor = f;
   %SetCode(f, function(m) {
     if (%IsConstructCall()) {
       if (!IS_UNDEFINED(m)) this.message = ToString(m);
     } else {
       return new f(m);
     }
   });
 }
 
 $Math.__proto__ = global.Object.prototype;
 
 DefineError(function Error() { });
 DefineError(function TypeError() { });
 DefineError(function RangeError() { });
 DefineError(function SyntaxError() { });
 DefineError(function ReferenceError() { });
 DefineError(function EvalError() { });
 DefineError(function URIError() { });
 
 // Setup extra properties of the Error.prototype object.
 $Error.prototype.message = '';
 
-%AddProperty($Error.prototype, 'toString', function toString() {
+%SetProperty($Error.prototype, 'toString', function toString() {
   var type = this.type;
   if (type && !this.hasOwnProperty("message")) {
     return this.name + ": " + FormatMessage({ type: type, args: this.arguments });
   }
   var message = this.message;
   return this.name + (message ? (": " + message) : "");
 }, DONT_ENUM);
 
 
 // Boilerplate for exceptions for stack overflows. Used from
 // Top::StackOverflow().
 const kStackOverflowBoilerplate = MakeRangeError('stack_overflow', []);