Remove MIPS support

runtime/vm/instructions.h

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef RUNTIME_VM_INSTRUCTIONS_H_
 #define RUNTIME_VM_INSTRUCTIONS_H_
 
 #include "vm/globals.h"
 
 #if defined(TARGET_ARCH_IA32)
 #include "vm/instructions_ia32.h"
 #elif defined(TARGET_ARCH_X64)
 #include "vm/instructions_x64.h"
 #elif defined(TARGET_ARCH_ARM)
 #include "vm/instructions_arm.h"
 #elif defined(TARGET_ARCH_ARM64)
 #include "vm/instructions_arm64.h"
-#elif defined(TARGET_ARCH_MIPS)
-#include "vm/instructions_mips.h"
 #elif defined(TARGET_ARCH_DBC)
 #include "vm/instructions_dbc.h"
 #else
 #error Unknown architecture.
 #endif
 
 namespace dart {
 
 class Object;
 class Code;
 
 bool DecodeLoadObjectFromPoolOrThread(uword pc, const Code& code, Object* obj);
 
 }  // namespace dart
 
 #endif  // RUNTIME_VM_INSTRUCTIONS_H_