[turbofan] fix vreg mapping for instruction selector tests

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 810 matching lines @@
 
   BasicBlock* GetContainingLoop(BasicBlock* block) {
     return block->loop_header();
   }
 
   int GetLoopEnd(BasicBlock* block) const { return block->loop_end(); }
 
   BasicBlock* GetBasicBlock(int instruction_index);
 
   int GetVirtualRegister(const Node* node);
+  // TODO(dcarney): find a way to remove this.
+  const int* GetNodeMapForTesting() const { return node_map_; }
 
   bool IsReference(int virtual_register) const;
   bool IsDouble(int virtual_register) const;
 
   void MarkAsReference(int virtual_register);
   void MarkAsDouble(int virtual_register);
 
   void AddGapMove(int index, InstructionOperand* from, InstructionOperand* to);
 
   Label* GetLabel(BasicBlock* block);
@@ skipping 88 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_