fn try_write_constant<'tcx>(
    ecx: &mut InterpCx<'_, 'tcx, DummyMachine>,
    dest: &PlaceTy<'tcx>,
    place: PlaceIndex,
    ty: Ty<'tcx>,
    state: &State<FlatSet<Scalar>>,
    map: &Map
) -> InterpResult<'tcx>