mesa: flush bitmap caches when changing scissors or window rects state

mesa: flush bitmap caches when changing scissors or window rects state

If we change the sate without flushing the bitmap cache, the cache might be
rendered with the new scissor, which excludes some parts that should've
been rendered with the old state, and vice versa.

Cc: mesa-stable
Closes: https://gitlab.freedesktop.org/mesa/mesa/-/issues/6233

Signed-off-by: Sviatoslav Peleshko <sviatoslav.peleshko@globallogic.com>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/15881>