Make maps in monomorphic IC stubs weak.

src/code-stubs.h

 // 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 210 matching lines @@
   // Returns whether the code generated for this stub needs to be allocated as
   // a fixed (non-moveable) code object.
   virtual bool NeedsImmovableCode() { return false; }
 
   virtual void PrintBaseName(StringStream* stream);
   virtual void PrintState(StringStream* stream) { }
 
  private:
   // Perform bookkeeping required after code generation when stub code is
   // initially generated.
-  void RecordCodeGeneration(Code* code, Isolate* isolate);
+  void RecordCodeGeneration(Handle<Code> code, Isolate* isolate);
 
   // Finish the code object after it has been generated.
   virtual void FinishCode(Handle<Code> code) { }
 
   // Activate newly generated stub. Is called after
   // registering stub in the stub cache.
   virtual void Activate(Code* code) { }
 
   // BinaryOpStub needs to override this.
   virtual Code::Kind GetCodeKind() const;
@@ skipping 2282 matching lines @@
 
 
 class CallDescriptors {
  public:
   static void InitializeForIsolate(Isolate* isolate);
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_CODE_STUBS_H_