BitmapActionDiscard
llbitmap_state_machine(llbitmap, start, end, BitmapActionDiscard);
[BitmapActionDiscard] = BitNone,
[BitmapActionDiscard] = BitUnwritten,
[BitmapActionDiscard] = BitUnwritten,
[BitmapActionDiscard] = BitUnwritten,
[BitmapActionDiscard] = BitUnwritten,
[BitmapActionDiscard] = BitUnwritten,
[BitmapActionDiscard] = BitUnwritten,
[BitmapActionDiscard] = BitUnwritten,