Initial revision of ARM simulator and (empty) MIPS simulator.

runtime/vm/simulator.h

Index: runtime/vm/simulator.h
===================================================================
--- runtime/vm/simulator.h	(revision 0)
+++ runtime/vm/simulator.h	(revision 0)
@@ -0,0 +1,36 @@
+// Copyright (c) 2013, 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_SIMULATOR_H_
+#define VM_SIMULATOR_H_
+
+#include "vm/globals.h"
+
+#if defined(TARGET_ARCH_IA32)
+// No simulator used.
+
+#elif defined(TARGET_ARCH_X64)
+// No simulator used.
+
+#elif defined(TARGET_ARCH_ARM)
+#if defined(HOST_ARCH_ARM)
+// No simulator used.
+#else
+#define USING_SIMULATOR 1
+#include "vm/simulator_arm.h"
+#endif
+
+#elif defined(TARGET_ARCH_MIPS)
+#if defined(HOST_ARCH_MIPS)
+// No simulator used.
+#else
+#define USING_SIMULATOR 1
+#include "vm/simulator_mips.h"
+#endif
+
+#else
+#error Unknown architecture.
+#endif
+
+#endif  // VM_SIMULATOR_H_