Use holder dictionary-mode to detect FAST or NORMAL

src/ic.cc

 // 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
@@ skipping 822 matching lines @@
 Handle<Code> IC::ComputeHandler(LookupResult* lookup,
                                 Handle<Object> object,
                                 Handle<String> name,
                                 Handle<Object> value) {
   InlineCacheHolderFlag cache_holder = GetCodeCacheForObject(*object);
   Handle<HeapObject> stub_holder(GetCodeCacheHolder(
       isolate(), *object, cache_holder));
 
   Handle<Code> code = isolate()->stub_cache()->FindHandler(
       name, handle(stub_holder->map()), kind(), cache_holder,
-      lookup->IsNormal() ? Code::NORMAL : Code::FAST);
+      lookup->holder()->HasFastProperties() ? Code::FAST : Code::NORMAL);
   if (!code.is_null()) {
 #ifdef DEBUG
     Handle<Code> compiled = CompileHandler(
         lookup, object, name, value, cache_holder);
     ASSERT(compiled->flags() == code->flags());
 #endif
     return code;
   }
 
   code = CompileHandler(lookup, object, name, value, cache_holder);
@@ skipping 1947 matching lines @@
 #undef ADDR
 };
 
 
 Address IC::AddressFromUtilityId(IC::UtilityId id) {
   return IC_utilities[id];
 }
 
 
 } }  // namespace v8::internal