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

runtime/lib/isolate.cc

-// 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 "platform/assert.h"
 #include "vm/bootstrap_natives.h"
-
-#include "vm/assert.h"
 #include "vm/class_finalizer.h"
 #include "vm/dart.h"
 #include "vm/dart_api_impl.h"
 #include "vm/dart_entry.h"
 #include "vm/exceptions.h"
 #include "vm/longjump.h"
 #include "vm/object.h"
 #include "vm/object_store.h"
 #include "vm/port.h"
 #include "vm/resolver.h"
@@ skipping 319 matching lines @@
   intptr_t send_id = Smi::CheckedHandle(arguments->At(0)).Value();
   intptr_t reply_id = Smi::CheckedHandle(arguments->At(1)).Value();
   // TODO(iposva): Allow for arbitrary messages to be sent.
   uint8_t* data = SerializeObject(Instance::CheckedHandle(arguments->At(2)));
 
   // TODO(turnidge): Throw an exception when the return value is false?
   PortMap::PostMessage(send_id, reply_id, Api::CastMessage(data));
 }
 
 }  // namespace dart