Handlify the stub cache lookup and patching for CallIC and KeyedCallIC.

src/ic.h

 // 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 198 matching lines @@
                                             Handle<Object> object,
                                             Handle<String> name);
 
  protected:
   Code::Kind kind_;
 
   bool TryUpdateExtraICState(LookupResult* lookup,
                              Handle<Object> object,
                              Code::ExtraICState* extra_ic_state);
 
-  MUST_USE_RESULT MaybeObject* ComputeMonomorphicStub(
-      LookupResult* lookup,
-      State state,
-      Code::ExtraICState extra_ic_state,
-      Handle<Object> object,
-      Handle<String> name);
+  // Compute a monomorphic stub if possible, otherwise return a null handle.
+  Handle<Code> ComputeMonomorphicStub(LookupResult* lookup,
+                                      State state,
+                                      Code::ExtraICState extra_state,
+                                      Handle<Object> object,
+                                      Handle<String> name);
 
   // Update the inline cache and the global stub cache based on the lookup
   // result.
   void UpdateCaches(LookupResult* lookup,
                     State state,
                     Code::ExtraICState extra_ic_state,
                     Handle<Object> object,
                     Handle<String> name);
 
   // Returns a JSFunction if the object can be called as a function, and
@@ skipping 500 matching lines @@
   void patch(Code* code);
 };
 
 
 // Helper for BinaryOpIC and CompareIC.
 void PatchInlinedSmiCode(Address address);
 
 } }  // namespace v8::internal
 
 #endif  // V8_IC_H_