if it's known on init that there are no variants for nonseamless cubes,
or inlined values, or decomposed vertex attrs, then shader keys can be
compressed more optimally to reduce the work needed on program updates
more importantly, this reduces the total hash value for all the shader
modules to a single uint32_t (technically 24 bits), which is much better
than having to manage and incrementally add all the separte module hashes
...but for now using this is incompatible with gpl, so disable that
Reviewed-by: Adam Jackson <ajax@redhat.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/18786>
Mike Blumenkrantz
325c703624