[turbofan] Avoid large deopt blocks

src/compiler/instruction.h

 // Copyright 2014 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_COMPILER_INSTRUCTION_H_
 #define V8_COMPILER_INSTRUCTION_H_
 
 #include <deque>
 #include <iosfwd>
 #include <map>
@@ skipping 1282 matching lines @@
 
   bool needs_frame() const { return needs_frame_; }
   void mark_needs_frame() { needs_frame_ = true; }
 
   bool must_construct_frame() const { return must_construct_frame_; }
   void mark_must_construct_frame() { must_construct_frame_ = true; }
 
   bool must_deconstruct_frame() const { return must_deconstruct_frame_; }
   void mark_must_deconstruct_frame() { must_deconstruct_frame_ = true; }
 
-  void set_last_deferred(RpoNumber last) { last_deferred_ = last; }
-  RpoNumber last_deferred() const { return last_deferred_; }
-
  private:
   Successors successors_;
   Predecessors predecessors_;
   PhiInstructions phis_;
   RpoNumber ao_number_;  // Assembly order number.
   const RpoNumber rpo_number_;
   const RpoNumber loop_header_;
   const RpoNumber loop_end_;
   int32_t code_start_;   // start index of arch-specific code.
   int32_t code_end_;     // end index of arch-specific code.
   const bool deferred_;  // Block contains deferred code.
   const bool handler_;   // Block is a handler entry point.
   bool needs_frame_;
   bool must_construct_frame_;
   bool must_deconstruct_frame_;
-  RpoNumber last_deferred_;
 };
 
 class InstructionSequence;
 
 struct PrintableInstructionBlock {
   const RegisterConfiguration* register_configuration_;
   const InstructionBlock* block_;
   const InstructionSequence* code_;
 };
 
@@ skipping 204 matching lines @@
 
 
 std::ostream& operator<<(std::ostream& os,
                          const PrintableInstructionSequence& code);
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_INSTRUCTION_H_