Add ES5 Object.isExtensible and Object.preventExtensions.

src/runtime.cc

 // Copyright 2006-2009 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 660 matching lines @@
     elms->set(VALUE_INDEX, result.GetLazyValue());
     elms->set(WRITABLE_INDEX, Heap::ToBoolean(!result.IsReadOnly()));
   }
 
   elms->set(ENUMERABLE_INDEX, Heap::ToBoolean(!result.IsDontEnum()));
   elms->set(CONFIGURABLE_INDEX, Heap::ToBoolean(!result.IsDontDelete()));
   return *desc;
 }
 
 
+static Object* Runtime_PreventExtensions(Arguments args) {
+  ASSERT(args.length() == 1);
+  CONVERT_CHECKED(JSObject, obj, args[0]);
+  return obj->PreventExtensions();
+}
+
 static Object* Runtime_IsExtensible(Arguments args) {
   ASSERT(args.length() == 1);
   CONVERT_CHECKED(JSObject, obj, args[0]);
   return obj->map()->is_extensible() ?  Heap::true_value()
                                      : Heap::false_value();
 }
 
 
 static Object* Runtime_RegExpCompile(Arguments args) {
   HandleScope scope;
@@ skipping 9704 matching lines @@
   } else {
     // Handle last resort GC and make sure to allow future allocations
     // to grow the heap without causing GCs (if possible).
     Counters::gc_last_resort_from_js.Increment();
     Heap::CollectAllGarbage(false);
   }
 }
 
 
 } }  // namespace v8::internal