Fix crash in debug builds introduced with r21110.

src/x64/lithium-codegen-x64.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_X64_LITHIUM_CODEGEN_X64_H_
 #define V8_X64_LITHIUM_CODEGEN_X64_H_
 
 #include "x64/lithium-x64.h"
 
 #include "checks.h"
@@ skipping 109 matching lines @@
 
   void EmitClassOfTest(Label* if_true,
                        Label* if_false,
                        Handle<String> class_name,
                        Register input,
                        Register temporary,
                        Register scratch);
 
   int GetStackSlotCount() const { return chunk()->spill_slot_count(); }
 
-  void Abort(BailoutReason reason);
-
   void AddDeferredCode(LDeferredCode* code) { deferred_.Add(code, zone()); }
 
 
   void SaveCallerDoubles();
   void RestoreCallerDoubles();
 
   // Code generation passes.  Returns true if code generation should
   // continue.
   void GenerateBodyInstructionPre(LInstruction* instr) V8_OVERRIDE;
   void GenerateBodyInstructionPost(LInstruction* instr) V8_OVERRIDE;
@@ skipping 248 matching lines @@
   Label entry_;
   Label exit_;
   Label done_;
   Label* external_exit_;
   int instruction_index_;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_X64_LITHIUM_CODEGEN_X64_H_