MIPS64: Prepare additonal code for turbofan landing.

src/mips64/constants-mips64.cc

 // Copyright 2011 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/v8.h"
 
 #if V8_TARGET_ARCH_MIPS64
 
 #include "src/mips64/constants-mips64.h"
 
@@ skipping 269 matching lines @@
         case CLZ:
           return kRegisterType;
         default:
           return kUnsupported;
       }
       break;
     case SPECIAL3:
       switch (FunctionFieldRaw()) {
         case INS:
         case EXT:
+        case DEXT:
           return kRegisterType;
         default:
           return kUnsupported;
       }
       break;
     case COP1:    // Coprocessor instructions.
       switch (RsFieldRawNoAssert()) {
         case BC1:   // Branch on coprocessor condition.
         case BC1EQZ:
         case BC1NEZ:
@@ skipping 53 matching lines @@
     default:
       return kUnsupported;
   }
   return kUnsupported;
 }
 
 
 } }   // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_MIPS64