Move utils.h and utils.cc from runtime/vm to runtime/platform

runtime/vm/debuginfo.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_DEBUGINFO_H_
 #define VM_DEBUGINFO_H_
 
 #include "platform/assert.h"
+#include "platform/utils.h"
 #include "vm/globals.h"
-#include "vm/utils.h"
 
 namespace dart {
 
 // DebugInfo is used to generate minimal debug information containing code,
 // symbols, and line numbers for generated code in the dart VM. This information
 // can be used in two ways:
 // - for debugging using a debugger
 // - for generating information to be read by pprof to analyze Dart programs.
 class DebugInfo {
  public:
@@ skipping 72 matching lines @@
  private:
   void* handle_;
   DebugInfo();
 
   DISALLOW_COPY_AND_ASSIGN(DebugInfo);
 };
 
 }  // namespace dart
 
 #endif  // VM_DEBUGINFO_H_