Make the runtime entry for setting/changing accessors "atomic".

test/mjsunit/object-define-property.js

-// Copyright 2010 the V8 project authors. All rights reserved.
+// Copyright 2012 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
 //       with the distribution.
@@ skipping 484 matching lines @@
 
 try {
   %DefineOrRedefineDataProperty({}, null, null, null);
 } catch (e) {
   assertTrue(/illegal access/.test(e));
 }
 
 // Defining properties null should fail even when we have
 // other allowed values
 try {
-  %DefineOrRedefineAccessorProperty(null, 'foo', 0, func, 0);
+  %DefineOrRedefineAccessorProperty(null, 'foo', func, null, 0);
 } catch (e) {
   assertTrue(/illegal access/.test(e));
 }
 
 try {
   %DefineOrRedefineDataProperty(null, 'foo', 0, 0);
 } catch (e) {
   assertTrue(/illegal access/.test(e));
 }
 
@@ skipping 561 matching lines @@
 
 
 // Regression test: We should never observe the hole value.
 var objectWithGetter = {};
 objectWithGetter.__defineGetter__('foo', function() {});
 assertEquals(undefined, objectWithGetter.__lookupSetter__('foo'));
 
 var objectWithSetter = {};
 objectWithSetter.__defineSetter__('foo', function(x) {});
 assertEquals(undefined, objectWithSetter.__lookupGetter__('foo'));