Emit comment with instruction+reason before deopt calls.

src/lithium-codegen.h

 // Copyright 2013 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_LITHIUM_CODEGEN_H_
 #define V8_LITHIUM_CODEGEN_H_
 
 #include "src/v8.h"
 
 #include "src/compiler.h"
@@ skipping 15 matching lines @@
   MacroAssembler* masm() const { return masm_; }
   CompilationInfo* info() const { return info_; }
   Isolate* isolate() const { return info_->isolate(); }
   Factory* factory() const { return isolate()->factory(); }
   Heap* heap() const { return isolate()->heap(); }
   Zone* zone() const { return zone_; }
   LPlatformChunk* chunk() const { return chunk_; }
   HGraph* graph() const;
 
   void FPRINTF_CHECKING Comment(const char* format, ...);
+  void DeoptComment(const char* mnemonic, const char* reason);
 
   bool GenerateBody();
   virtual void GenerateBodyInstructionPre(LInstruction* instr) {}
   virtual void GenerateBodyInstructionPost(LInstruction* instr) {}
 
   virtual void EnsureSpaceForLazyDeopt(int space_needed) = 0;
   virtual void RecordAndWritePosition(int position) = 0;
 
   int GetNextEmittedBlock() const;
 
@@ skipping 31 matching lines @@
 
   // Methods for code dependencies.
   void AddDeprecationDependency(Handle<Map> map);
   void AddStabilityDependency(Handle<Map> map);
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_LITHIUM_CODEGEN_H_