Implement byte swapping instructions on MIPS32 and MIPS64.

src/mips64/constants-mips64.h

 // Copyright 2012 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_MIPS_CONSTANTS_H_
 #define  V8_MIPS_CONSTANTS_H_
 
 #include "src/base/logging.h"
 #include "src/base/macros.h"
 #include "src/globals.h"
@@ skipping 1219 matching lines @@
         case DINS:
         case EXT:
         case DEXT:
         case DEXTM:
         case DEXTU:
           return kRegisterType;
         case BSHFL: {
           int sa = SaFieldRaw() >> kSaShift;
           switch (sa) {
             case BITSWAP:
-              return kRegisterType;
             case WSBH:
             case SEB:
             case SEH:
-              return kUnsupported;
+              return kRegisterType;
           }
           sa >>= kBp2Bits;
           switch (sa) {
             case ALIGN:
               return kRegisterType;
             default:
               return kUnsupported;
           }
         }
         case DBSHFL: {
           int sa = SaFieldRaw() >> kSaShift;
           switch (sa) {
             case DBITSWAP:
-              return kRegisterType;
             case DSBH:
             case DSHD:
-              return kUnsupported;
+              return kRegisterType;
           }
           sa = SaFieldRaw() >> kSaShift;
           sa >>= kBp3Bits;
           switch (sa) {
             case DALIGN:
               return kRegisterType;
             default:
               return kUnsupported;
           }
         }
@@ skipping 28 matching lines @@
   }
   return kUnsupported;
 }
 
 #undef OpcodeToBitNumber
 #undef FunctionFieldToBitNumber
 }  // namespace internal
 }  // namespace v8
 
 #endif    // #ifndef V8_MIPS_CONSTANTS_H_