X87: [turbofan] Store nodes use only MachineRepresentation, not MachineType.

  port 56673804 (r32803)

  original commit message:

BUG=

Review URL: https://codereview.chromium.org/1524063002

Cr-Commit-Position: refs/heads/master@{#32854}

src/compiler/x87/instruction-selector-x87.cc

@@ -174,9 +174,9 @@ void InstructionSelector::VisitStore(Node* node) {
   Node* index = node->InputAt(1);
   Node* value = node->InputAt(2);
 
-  StoreRepresentation store_rep = OpParameter<StoreRepresentation>(node);
+  StoreRepresentation store_rep = StoreRepresentationOf(node->op());
   WriteBarrierKind write_barrier_kind = store_rep.write_barrier_kind();
-  MachineRepresentation rep = store_rep.machine_type().representation();
+  MachineRepresentation rep = store_rep.representation();
 
   if (write_barrier_kind != kNoWriteBarrier) {
     DCHECK_EQ(MachineRepresentation::kTagged, rep);
@@ -305,8 +305,7 @@ void InstructionSelector::VisitCheckedLoad(Node* node) {
 
 
 void InstructionSelector::VisitCheckedStore(Node* node) {
-  MachineRepresentation rep =
-      CheckedStoreRepresentationOf(node->op()).representation();
+  MachineRepresentation rep = CheckedStoreRepresentationOf(node->op());
   X87OperandGenerator g(this);
   Node* const buffer = node->InputAt(0);
   Node* const offset = node->InputAt(1);