Make accessors for oddball objects return Oddball* instead of Object*.

src/ic.cc

 // Copyright 2011 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 149 matching lines @@
       original_code->instruction_start() - code->instruction_start();
   return addr + delta;
 }
 #endif
 
 
 static bool HasNormalObjectsInPrototypeChain(Isolate* isolate,
                                              LookupResult* lookup,
                                              Object* receiver) {
   Object* end = lookup->IsProperty()
-      ? lookup->holder() : isolate->heap()->null_value();
+      ? lookup->holder() : Object::cast(isolate->heap()->null_value());
   for (Object* current = receiver;
        current != end;
        current = current->GetPrototype()) {
     if (current->IsJSObject() &&
         !JSObject::cast(current)->HasFastProperties() &&
         !current->IsJSGlobalProxy() &&
         !current->IsJSGlobalObject()) {
       return true;
     }
   }
@@ skipping 2327 matching lines @@
 #undef ADDR
 };
 
 
 Address IC::AddressFromUtilityId(IC::UtilityId id) {
   return IC_utilities[id];
 }
 
 
 } }  // namespace v8::internal