QQmlApplicationEngine: use-after-free when loading a component

QQmlApplicationEnginePrivate::_q_finishLoad deletes the just-loaded component at the end of the function. Unfortunately, the component is then used again inside QQmlComponentPrivate::typeDataReady:

    emit q->statusChanged(q->status());    <--- QQmlApplicationEngine deletes q
    emit q->progressChanged(progress);     <--- q is used