[Turbofan] Add Simd128 registers to RegisterConfiguration.

src/machine-type.h

 // 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.
 
 #ifndef V8_MACHINE_TYPE_H_
 #define V8_MACHINE_TYPE_H_
 
 #include <iosfwd>
 
 #include "src/base/bits.h"
 #include "src/globals.h"
 #include "src/signature.h"
 #include "src/zone.h"
 
 namespace v8 {
 namespace internal {
 
 enum class MachineRepresentation : uint8_t {
   kNone,
   kBit,
   kWord8,
   kWord16,
   kWord32,
   kWord64,
   kFloat32,
-  kFloat64,
-  kSimd128,
+  kFloat64,  // must follow kFloat32
+  kSimd128,  // must follow kFloat64
   kTagged
 };
 
 enum class MachineSemantic : uint8_t {
   kNone,
   kBool,
   kInt32,
   kUint32,
   kInt64,
   kUint64,
@@ skipping 167 matching lines @@
   UNREACHABLE();
   return -1;
 }
 
 typedef Signature<MachineType> MachineSignature;
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_MACHINE_TYPE_H_