Make IC patching resilient to flushing of the original target() ic.

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 233 matching lines @@
   friend class BreakPointIterator;
 };
 
 
 class PlatformCodeStub : public CodeStub {
  public:
   // Retrieve the code for the stub. Generate the code if needed.
   virtual Handle<Code> GenerateCode();
 
   virtual int GetCodeKind() { return Code::STUB; }
+  virtual int GetStubFlags() { return -1; }
 
  protected:
   // Generates the assembler code for the stub.
   virtual void Generate(MacroAssembler* masm) = 0;
 };
 
 
 struct CodeStubInterfaceDescriptor {
   CodeStubInterfaceDescriptor()
       : register_param_count_(-1),
@@ skipping 391 matching lines @@
   virtual void Generate(MacroAssembler* masm);
 
  private:
   virtual CodeStub::Major MajorKey() { return StoreArrayLength; }
 };
 
 
 class HandlerStub: public ICStub {
  public:
   explicit HandlerStub(Code::Kind kind) : ICStub(kind) { }
-
- protected:
-  virtual Code::ExtraICState GetExtraICState() {
-    return Code::HANDLER_FRAGMENT;
-  }
+  virtual int GetCodeKind() { return Code::STUB; }
+  virtual int GetStubFlags() { return kind(); }
 };
 
 
 class LoadFieldStub: public HandlerStub {
  public:
   LoadFieldStub(Register reg, bool inobject, int index)
       : HandlerStub(Code::LOAD_IC),
         reg_(reg),
         inobject_(inobject),
         index_(index) { }
@@ skipping 934 matching lines @@
 
   // The current function entry hook.
   static FunctionEntryHook entry_hook_;
 
   DISALLOW_COPY_AND_ASSIGN(ProfileEntryHookStub);
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_CODE_STUBS_H_