debugger: adjust dummy test ObjectPrivate layout for Qt 4.8 changes

Change-Id: I35914e79dce4894a5ec7f0ee656b86e4ce13e2a9
Reviewed-on: http://codereview.qt.nokia.com/365


Reviewed-by: Qt Sanity Bot <qt_sanity_bot@ovi.com>
Reviewed-by: hjk <qthjk@ovi.com>