pan/bi: Add load_output support

This is mapped to the LD_TILE instruction. Note that multi-sample RTs
are not supported yet.

Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7151>
7 files changed