[turbofan] Allow stores bigger than tagged size in store-store elimination.

src/machine-type.cc

Index: src/machine-type.cc
diff --git a/src/machine-type.cc b/src/machine-type.cc
index fcc3e9797375bccd8b4c6b7a3c3e67a3d095d7db..7c4ddd3967f88cdc9bc6ee2488bca743318f6383 100644
--- a/src/machine-type.cc
+++ b/src/machine-type.cc
@@ -9,33 +9,36 @@ namespace v8 {
 namespace internal {
 
 std::ostream& operator<<(std::ostream& os, MachineRepresentation rep) {
+  return os << MachineReprToString(rep);
+}
+
+const char* MachineReprToString(MachineRepresentation rep) {
   switch (rep) {
     case MachineRepresentation::kNone:
-      return os << "kMachNone";
+      return "kMachNone";
     case MachineRepresentation::kBit:
-      return os << "kRepBit";
+      return "kRepBit";
     case MachineRepresentation::kWord8:
-      return os << "kRepWord8";
+      return "kRepWord8";
     case MachineRepresentation::kWord16:
-      return os << "kRepWord16";
+      return "kRepWord16";
     case MachineRepresentation::kWord32:
-      return os << "kRepWord32";
+      return "kRepWord32";
     case MachineRepresentation::kWord64:
-      return os << "kRepWord64";
+      return "kRepWord64";
     case MachineRepresentation::kFloat32:
-      return os << "kRepFloat32";
+      return "kRepFloat32";
     case MachineRepresentation::kFloat64:
-      return os << "kRepFloat64";
+      return "kRepFloat64";
     case MachineRepresentation::kSimd128:
-      return os << "kRepSimd128";
+      return "kRepSimd128";
     case MachineRepresentation::kTagged:
-      return os << "kRepTagged";
+      return "kRepTagged";
   }
   UNREACHABLE();
-  return os;
+  return nullptr;
 }
 
-
 std::ostream& operator<<(std::ostream& os, MachineSemantic type) {
   switch (type) {
     case MachineSemantic::kNone: