Reverts refactoring of CPU feature detection for

runtime/vm/cpu_x64.h

Index: runtime/vm/cpu_x64.h
===================================================================
--- runtime/vm/cpu_x64.h	(revision 32559)
+++ runtime/vm/cpu_x64.h	(working copy)
@@ -1,61 +0,0 @@
-// 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_X64_H_
-#define VM_CPU_X64_H_
-
-#include "vm/allocation.h"
-#include "vm/flags.h"
-
-namespace dart {
-
-DECLARE_FLAG(bool, use_sse41);
-
-class HostCPUFeatures : public AllStatic {
- public:
-  static void InitOnce();
-  static char* hardware() {
-    DEBUG_ASSERT(initialized_);
-    return hardware_;
-  }
-  static bool sse2_supported() {
-    DEBUG_ASSERT(initialized_);
-    return sse2_supported_;
-  }
-  static bool sse4_1_supported() {
-    DEBUG_ASSERT(initialized_);
-    return sse4_1_supported_ && FLAG_use_sse41;
-  }
-
- private:
-  static const uint64_t kSSE2BitMask = static_cast<uint64_t>(1) << 26;
-  static const uint64_t kSSE4_1BitMask = static_cast<uint64_t>(1) << 51;
-  static char* hardware_;
-  static bool sse2_supported_;
-  static bool sse4_1_supported_;
-#if defined(DEBUG)
-  static bool initialized_;
-#endif
-};
-
-class TargetCPUFeatures : public AllStatic {
- public:
-  static void InitOnce() { HostCPUFeatures::InitOnce(); }
-  static char* hardware() {
-    return HostCPUFeatures::hardware();
-  }
-  static bool sse2_supported() {
-    return HostCPUFeatures::sse2_supported();
-  }
-  static bool sse4_1_supported() {
-    return HostCPUFeatures::sse4_1_supported();
-  }
-  static bool double_truncate_round_supported() {
-    return false;
-  }
-};
-
-}  // namespace dart
-
-#endif  // VM_CPU_X64_H_