Use ComputeHandlerFlags to find handlers, rather than manually encoding.

src/objects.cc

 // Copyright 2013 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 7493 matching lines @@
   Object* new_cache;
   { MaybeObject* maybe_new_cache = cache->Put(name, code);
     if (!maybe_new_cache->ToObject(&new_cache)) return maybe_new_cache;
   }
   set_normal_type_cache(new_cache);
   return this;
 }
 
 
 Object* CodeCache::Lookup(Name* name, Code::Flags flags) {
-  flags = Code::RemoveTypeFromFlags(flags);
-  Object* result = LookupDefaultCache(name, flags);
-  if (result->IsCode()) return result;
+  Object* result = LookupDefaultCache(name, Code::RemoveTypeFromFlags(flags));
+  if (result->IsCode()) {
+    if (Code::cast(result)->flags() == flags) return result;
+    return GetHeap()->undefined_value();
+  }
   return LookupNormalTypeCache(name, flags);
 }
 
 
 Object* CodeCache::LookupDefaultCache(Name* name, Code::Flags flags) {
   FixedArray* cache = default_cache();
   int length = cache->length();
   for (int i = 0; i < length; i += kCodeCacheEntrySize) {
     Object* key = cache->get(i + kCodeCacheEntryNameOffset);
     // Skip deleted elements.
@@ skipping 8953 matching lines @@
 #define ERROR_MESSAGES_TEXTS(C, T) T,
   static const char* error_messages_[] = {
       ERROR_MESSAGES_LIST(ERROR_MESSAGES_TEXTS)
   };
 #undef ERROR_MESSAGES_TEXTS
   return error_messages_[reason];
 }
 
 
 } }  // namespace v8::internal