Introduce runtime/platform directory for code shared between vm

runtime/bin/thread_pool_macos.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 BIN_THREAD_POOL_MACOS_H_
 #define BIN_THREAD_POOL_MACOS_H_
 
 #include <pthread.h>
 
-#include "vm/globals.h"
+#include "platform/globals.h"
 
 
 class TaskQueueData {
  private:
   TaskQueueData() {}
   ~TaskQueueData() {}
 
   pthread_mutex_t* mutex() { return &mutex_; }
   pthread_cond_t* cond() { return &cond_; }
 
@@ skipping 17 matching lines @@
 
   pthread_t* threads_;
 
   friend class ThreadPool;
 
   DISALLOW_ALLOCATION();
   DISALLOW_COPY_AND_ASSIGN(ThreadPoolData);
 };
 
 #endif  // BIN_THREAD_POOL_MACOS_H_