util: Change a codegenned switch statement to a nice little table.

This saves us 13 to 35kb on release drivers in my builds.

Acked-by: Matt Turner <mattst88@gmail.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5826>
3 files changed