[turbofan] move Node to vreg mapping to InstructionSelector

src/compiler/instruction.cc

Index: src/compiler/instruction.cc
diff --git a/src/compiler/instruction.cc b/src/compiler/instruction.cc
index 8ba4b0cc101b07c5be60e7842c8875ebfe41517b..7ee5a6961415164f718c7b71faf6a00ac803ae77 100644
--- a/src/compiler/instruction.cc
+++ b/src/compiler/instruction.cc
@@ -387,10 +387,8 @@ static void InitializeInstructionBlocks(Zone* zone, const Schedule* schedule,
 
 
 InstructionSequence::InstructionSequence(Zone* instruction_zone,
-                                         const Graph* graph,
                                          const Schedule* schedule)
     : zone_(instruction_zone),
-      node_map_(graph->NodeCount(), kNodeUnmapped, zone()),
       instruction_blocks_(static_cast<int>(schedule->rpo_order()->size()), NULL,
                           zone()),
       constants_(ConstantMap::key_compare(),
@@ -406,14 +404,6 @@ InstructionSequence::InstructionSequence(Zone* instruction_zone,
 }
 
 
-int InstructionSequence::GetVirtualRegister(const Node* node) {
-  if (node_map_[node->id()] == kNodeUnmapped) {
-    node_map_[node->id()] = NextVirtualRegister();
-  }
-  return node_map_[node->id()];
-}
-
-
 Label* InstructionSequence::GetLabel(BasicBlock::RpoNumber rpo) {
   return GetBlockStart(rpo)->label();
 }