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

runtime/vm/assembler.h

Index: runtime/vm/assembler.h
diff --git a/runtime/vm/assembler.h b/runtime/vm/assembler.h
index 1ad8417461e675bce6badab7eed9ff07d6336e88..fb8b0c324f2290d53f2ff56d6b8a105881aadf7e 100644
--- a/runtime/vm/assembler.h
+++ b/runtime/vm/assembler.h
@@ -1,12 +1,12 @@
-// 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_ASSEMBLER_H_
 #define VM_ASSEMBLER_H_
 
+#include "platform/assert.h"
 #include "vm/allocation.h"
-#include "vm/assert.h"
 #include "vm/globals.h"
 #include "vm/growable_array.h"
 #include "vm/object.h"