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

src/machine-type.cc

 // 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.
 
 #include "src/machine-type.h"
 #include "src/ostreams.h"
 
 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:
       return os << "kMachNone";
     case MachineSemantic::kBool:
       return os << "kTypeBool";
     case MachineSemantic::kInt32:
       return os << "kTypeInt32";
     case MachineSemantic::kUint32:
       return os << "kTypeUint32";
@@ skipping 19 matching lines @@
   } else if (type.semantic() == MachineSemantic::kNone) {
     return os << type.representation();
   } else {
     return os << type.representation() << "|" << type.semantic();
   }
   return os;
 }
 
 }  // namespace internal
 }  // namespace v8