pan/bi: Only lower once

Nothing in the optimization loop should remat the lowered instructions, so
there's no need to do it inside the loop.

Signed-off-by: Alyssa Rosenzweig <alyssa@collabora.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/20906>
1 file changed