Move assert.h/assert.cc from runtime/vm to runtime/platform

runtime/vm/thread.h

-// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
+// 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_THREAD_H_
 #define VM_THREAD_H_
 
-#include "vm/assert.h"
+#include "platform/assert.h"
 #include "vm/allocation.h"
 #include "vm/globals.h"
 #include "vm/isolate.h"
 
 // Declare the OS-specific types ahead of defining the generic classes.
 #if defined(TARGET_OS_LINUX)
 #include "vm/thread_linux.h"
 #elif defined(TARGET_OS_MACOS)
 #include "vm/thread_macos.h"
 #elif defined(TARGET_OS_WINDOWS)
@@ skipping 117 matching lines @@
  private:
   Monitor* const monitor_;
 
   DISALLOW_COPY_AND_ASSIGN(MonitorLocker);
 };
 
 }  // namespace dart
 
 
 #endif  // VM_THREAD_H_