[MIPS] Add thread-pointer to data addressing register list.

src/trusted/validator_mips/inst_classes.h

Index: src/trusted/validator_mips/inst_classes.h
diff --git a/src/trusted/validator_mips/inst_classes.h b/src/trusted/validator_mips/inst_classes.h
index 02617377c09742a2241df5c43e2d662b44851e72..ef8b27b9b88ec82a94ddfa9065d0f72d328e7188 100644
--- a/src/trusted/validator_mips/inst_classes.h
+++ b/src/trusted/validator_mips/inst_classes.h
@@ -1,8 +1,7 @@
 /*
- * Copyright 2012 The Native Client Authors.  All rights reserved.
- * Use of this source code is governed by a BSD-style license that can
- * be found in the LICENSE file.
- * Copyright 2012, Google Inc.
+ * Copyright (c) 2012 The Native Client 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 NATIVE_CLIENT_SRC_TRUSTED_VALIDATOR_MIPS_INST_CLASSES_H
@@ -90,7 +89,7 @@ class ClassDecoder {
    */
   virtual Register DestGprReg(const Instruction instr) const {
     UNREFERENCED_PARAMETER(instr);
-    return kRegisterNone;
+    return Register::None();
   }
 
   /*
@@ -151,7 +150,7 @@ class ClassDecoder {
    */
   virtual Register TargetReg(const Instruction instr) const {
     UNREFERENCED_PARAMETER(instr);
-    return kRegisterNone;
+    return Register::None();
   }
 
   /*
@@ -159,7 +158,7 @@ class ClassDecoder {
    */
   virtual Register BaseAddressRegister(const Instruction instr) const {
     UNREFERENCED_PARAMETER(instr);
-    return kRegisterNone;
+    return Register::None();
   }