[turbofan] fix block mapping in code comments

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 580 matching lines @@
 };
 
 
 // This special kind of gap move instruction represents the beginning of a
 // block of code.
 // TODO(titzer): move code_start and code_end from BasicBlock to here.
 class BlockStartInstruction FINAL : public GapInstruction {
  public:
   Label* label() { return &label_; }
   BasicBlock::RpoNumber rpo_number() const { return rpo_number_; }
+  BasicBlock::Id id() const { return id_; }
 
   static BlockStartInstruction* New(Zone* zone, BasicBlock* block) {
     void* buffer = zone->New(sizeof(BlockStartInstruction));
     return new (buffer) BlockStartInstruction(block);
   }
 
   static BlockStartInstruction* cast(Instruction* instr) {
     DCHECK(instr->IsBlockStart());
     return static_cast<BlockStartInstruction*>(instr);
   }
 
  private:
   explicit BlockStartInstruction(BasicBlock* block)
       : GapInstruction(kBlockStartInstruction),
+        id_(block->id()),
         rpo_number_(block->GetRpoNumber()) {}
 
+  BasicBlock::Id id_;
   BasicBlock::RpoNumber rpo_number_;
   Label label_;
 };
 
 
 class SourcePositionInstruction FINAL : public Instruction {
  public:
   static SourcePositionInstruction* New(Zone* zone, SourcePosition position) {
     void* buffer = zone->New(sizeof(SourcePositionInstruction));
     return new (buffer) SourcePositionInstruction(position);
@@ skipping 320 matching lines @@
   DeoptimizationVector deoptimization_entries_;
 };
 
 std::ostream& operator<<(std::ostream& os, const InstructionSequence& code);
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_INSTRUCTION_H_