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

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

Index: src/compiler/mips/instruction-selector-mips.cc
diff --git a/src/compiler/mips/instruction-selector-mips.cc b/src/compiler/mips/instruction-selector-mips.cc
index 94beec1e944658f462fae5b302b2a5a02d5c5f60..e3981a2bd6a6e1a3e3a62c6fe97838251e5a79c4 100644
--- a/src/compiler/mips/instruction-selector-mips.cc
+++ b/src/compiler/mips/instruction-selector-mips.cc
@@ -176,9 +176,9 @@ 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();
 
   // TODO(mips): I guess this could be done in a better way.
   if (write_barrier_kind != kNoWriteBarrier) {
@@ -845,8 +845,7 @@ void InstructionSelector::VisitCheckedLoad(Node* node) {
 
 
 void InstructionSelector::VisitCheckedStore(Node* node) {
-  MachineRepresentation rep =
-      CheckedStoreRepresentationOf(node->op()).representation();
+  MachineRepresentation rep = CheckedStoreRepresentationOf(node->op());
   MipsOperandGenerator g(this);
   Node* const buffer = node->InputAt(0);
   Node* const offset = node->InputAt(1);