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

runtime/vm/disassembler_arm.cc

Index: runtime/vm/disassembler_arm.cc
diff --git a/runtime/vm/disassembler_arm.cc b/runtime/vm/disassembler_arm.cc
index 9170d80491850a8adf030f85248618e41b3984ba..bea7a3af943a06cafe89c5b63629e9174b21e72c 100644
--- a/runtime/vm/disassembler_arm.cc
+++ b/runtime/vm/disassembler_arm.cc
@@ -1,13 +1,13 @@
-// 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.
 
+#include "vm/disassembler.h"
+
+#include "platform/assert.h"
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_ARM.
 #if defined(TARGET_ARCH_ARM)
 
-#include "vm/disassembler.h"
-
-#include "vm/assert.h"
 
 namespace dart {