pan/decode: Use unpacks for state descriptor

This is a win in terms of line of decoder code, but it's a regression in
terms of verbosity. That will be fixed when we teach the decode
autogeneration about defaults and non-canonical fields.

Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Reviewed-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6440>
1 file changed