Fix Kraken regression due to optimistic monomorphic element transitions

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 1584 matching lines @@
   bool is_transition_stub = IsTransitionStubKind(stub_kind);
   Handle<Map> receiver_map(receiver->map());
   Handle<Map> monomorphic_map = receiver_map;
   MapHandleList target_receiver_maps;
   if (ic_state == UNINITIALIZED || ic_state == PREMONOMORPHIC) {
     // Optimistically assume that ICs that haven't reached the MONOMORPHIC state
     // yet will do so and stay there.
     monomorphic = true;
   } else {
     GetReceiverMapsForStub(Handle<Code>(target()), &target_receiver_maps);
-    if (ic_state == MONOMORPHIC && is_transition_stub) {
+    if (ic_state == MONOMORPHIC && (is_transition_stub || stub_kind == LOAD)) {
       // The first time a receiver is seen that is a transitioned version of the
       // previous monomorphic receiver type, assume the new ElementsKind is the
       // monomorphic type. This benefits global arrays that only transition
       // once, and all call sites accessing them are faster if they remain
       // monomorphic. If this optimistic assumption is not true, the IC will
       // miss again and it will become polymorphic and support both the
       // untransitioned and transitioned maps.
       monomorphic = IsMoreGeneralElementsKindTransition(
           target_receiver_maps.at(0)->elements_kind(),
           receiver->GetElementsKind());
@@ skipping 1056 matching lines @@
 #undef ADDR
 };
 
 
 Address IC::AddressFromUtilityId(IC::UtilityId id) {
   return IC_utilities[id];
 }
 
 
 } }  // namespace v8::internal