Reverts refactoring of CPU feature detection for

runtime/vm/cpu_mips.h

-// Copyright (c) 2012, 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 VM_CPU_MIPS_H_
-#define VM_CPU_MIPS_H_
-
-#include "vm/allocation.h"
-
-namespace dart {
-
-// TargetCPUFeatures gives CPU features for the architecture that we are
-// generating code for. HostCPUFeatures gives the CPU features for the
-// architecture that we are actually running on. When the architectures
-// are the same, TargetCPUFeatures will query HostCPUFeatures. When they are
-// different (i.e. we are running in a simulator), HostCPUFeatures will
-// additionally mock the options needed for the target architecture so that
-// they may be altered for testing.
-
-class HostCPUFeatures: public AllStatic {
- public:
-  static void InitOnce();
-  static char* hardware() {
-    DEBUG_ASSERT(initialized_);
-    return hardware_;
-  }
-
- private:
-  static char* hardware_;
-#if defined(DEBUG)
-  static bool initialized_;
-#endif
-};
-
-class TargetCPUFeatures : public AllStatic {
- public:
-  static void InitOnce() { HostCPUFeatures::InitOnce(); }
-  static bool double_truncate_round_supported() { return false; }
-};
-
-}  // namespace dart
-
-#endif  // VM_CPU_MIPS_H_