Reapplying r5147 (caching maps for slow case objects)....

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 557 matching lines @@
       % JSFunctionResultCache::kEntrySize != 0) {
     return false;
   }
 #ifdef DEBUG
   reinterpret_cast<JSFunctionResultCache*>(this)->JSFunctionResultCacheVerify();
 #endif
   return true;
 }
 
 
+bool Object::IsNormalizedMapCache() {
+  if (!IsFixedArray()) return false;
+  if (FixedArray::cast(this)->length() != NormalizedMapCache::kEntries) {
+    return false;
+  }
+#ifdef DEBUG
+  reinterpret_cast<NormalizedMapCache*>(this)->NormalizedMapCacheVerify();
+#endif
+  return true;
+}
+
+
 bool Object::IsCompilationCacheTable() {
   return IsHashTable();
 }
 
 
 bool Object::IsCodeCacheHashTable() {
   return IsHashTable();
 }
 
 
@@ skipping 1065 matching lines @@
 
 
 // ------------------------------------
 // Cast operations
 
 
 CAST_ACCESSOR(FixedArray)
 CAST_ACCESSOR(DescriptorArray)
 CAST_ACCESSOR(SymbolTable)
 CAST_ACCESSOR(JSFunctionResultCache)
+CAST_ACCESSOR(NormalizedMapCache)
 CAST_ACCESSOR(CompilationCacheTable)
 CAST_ACCESSOR(CodeCacheHashTable)
 CAST_ACCESSOR(MapCache)
 CAST_ACCESSOR(String)
 CAST_ACCESSOR(SeqString)
 CAST_ACCESSOR(SeqAsciiString)
 CAST_ACCESSOR(SeqTwoByteString)
 CAST_ACCESSOR(ConsString)
 CAST_ACCESSOR(ExternalString)
 CAST_ACCESSOR(ExternalAsciiString)
@@ skipping 1793 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_