Make it possible to Crankshaft all kinds of stubs.

src/x64/code-stubs-x64.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 120 matching lines @@
   void GenerateNumberStubSub(MacroAssembler* masm);
   void GenerateNumberStubBitNot(MacroAssembler* masm);
   void GenerateHeapNumberCodeSub(MacroAssembler* masm, Label* slow);
   void GenerateHeapNumberCodeBitNot(MacroAssembler* masm, Label* slow);
 
   void GenerateGenericStub(MacroAssembler* masm);
   void GenerateGenericStubSub(MacroAssembler* masm);
   void GenerateGenericStubBitNot(MacroAssembler* masm);
   void GenerateGenericCodeFallback(MacroAssembler* masm);
 
-  virtual int GetCodeKind() { return Code::UNARY_OP_IC; }
+  virtual Code::Kind GetCodeKind() const { return Code::UNARY_OP_IC; }
 
   virtual InlineCacheState GetICState() {
     return UnaryOpIC::ToState(operand_type_);
   }
 
   virtual void FinishCode(Handle<Code> code) {
     code->set_unary_op_type(operand_type_);
   }
 };
 
@@ skipping 462 matching lines @@
   RememberedSetAction remembered_set_action_;
   SaveFPRegsMode save_fp_regs_mode_;
   Label slow_;
   RegisterAllocation regs_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_X64_CODE_STUBS_X64_H_