Add ES5 Object.isExtensible and Object.preventExtensions.

src/v8natives.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 727 matching lines @@
   }
   for (var i = 0; i < key_values.length; i += 2) {
     var key = key_values[i];
     var desc = key_values[i + 1];
     DefineOwnProperty(obj, key, desc, true);
   }
   return obj;
 }
 
 
+// ES5 section 15.2.3.10
+function ObjectPreventExtension(obj) {
+  if ((!IS_SPEC_OBJECT_OR_NULL(obj) || IS_NULL_OR_UNDEFINED(obj)) &&
+      !IS_UNDETECTABLE(obj)) {
+    throw MakeTypeError("obj_ctor_property_non_object", ["preventExtension"]);
+  }
+  %PreventExtensions(obj);
+  return obj;
+}
+
+
+// ES5 section 15.2.3.13
+function ObjectIsExtensible(obj) {
+  if ((!IS_SPEC_OBJECT_OR_NULL(obj) || IS_NULL_OR_UNDEFINED(obj)) &&
+      !IS_UNDETECTABLE(obj)) {
+    throw MakeTypeError("obj_ctor_property_non_object", ["preventExtension"]);
+  }
+  return %IsExtensible(obj);
+}
+
+
 %SetCode($Object, function(x) {
   if (%_IsConstructCall()) {
     if (x == null) return this;
     return ToObject(x);
   } else {
     if (x == null) return { };
     return ToObject(x);
   }
 });
 
@@ skipping 15 matching lines @@
     "__defineSetter__", ObjectDefineSetter,
     "__lookupSetter__", ObjectLookupSetter
   ));
   InstallFunctions($Object, DONT_ENUM, $Array(
     "keys", ObjectKeys,
     "create", ObjectCreate,
     "defineProperty", ObjectDefineProperty,
     "defineProperties", ObjectDefineProperties,
     "getPrototypeOf", ObjectGetPrototypeOf,
     "getOwnPropertyDescriptor", ObjectGetOwnPropertyDescriptor,
-    "getOwnPropertyNames", ObjectGetOwnPropertyNames
+    "getOwnPropertyNames", ObjectGetOwnPropertyNames,
+    "isExtensible", ObjectIsExtensible,
+    "preventExtensions", ObjectPreventExtension
   ));
 }
 
 SetupObject();
 
 
 // ----------------------------------------------------------------------------
 // Boolean
 
 function BooleanToString() {
@@ skipping 247 matching lines @@
 
 // ----------------------------------------------------------------------------
 
 function SetupFunction() {
   InstallFunctions($Function.prototype, DONT_ENUM, $Array(
     "toString", FunctionToString
   ));
 }
 
 SetupFunction();