Add ES5 Object.isExtensible and Object.preventExtensions.

src/objects-inl.h

 // 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 2171 matching lines @@
     set_bit_field(bit_field() & ~(1 << kIsAccessCheckNeeded));
   }
 }
 
 
 bool Map::is_access_check_needed() {
   return ((1 << kIsAccessCheckNeeded) & bit_field()) != 0;
 }
 
 
+void Map::set_is_extensible(bool value) {
+  if (value) {
+    set_bit_field2(bit_field2() | (1 << kIsExtensible));
+  } else {
+    set_bit_field2(bit_field2() & ~(1 << kIsExtensible));
+  }
+}
+
+bool Map::is_extensible() {
+  return ((1 << kIsExtensible) & bit_field2()) != 0;
+}
+
+
+
 Code::Flags Code::flags() {
   return static_cast<Flags>(READ_INT_FIELD(this, kFlagsOffset));
 }
 
 
 void Code::set_flags(Code::Flags flags) {
   STATIC_ASSERT(Code::NUMBER_OF_KINDS <= (kFlagsKindMask >> kFlagsKindShift)+1);
   // Make sure that all call stubs have an arguments count.
   ASSERT((ExtractKindFromFlags(flags) != CALL_IC &&
           ExtractKindFromFlags(flags) != KEYED_CALL_IC) ||
@@ skipping 1052 matching lines @@
 #undef WRITE_INT_FIELD
 #undef READ_SHORT_FIELD
 #undef WRITE_SHORT_FIELD
 #undef READ_BYTE_FIELD
 #undef WRITE_BYTE_FIELD
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_INL_H_