Gallium refactoring: Part 3

Hi all,

Gitlab is back enough for discussion and review. If you are a
developer/maintainer for a gallium driver/frontend/util/bug, you should be
checking out this MR from a couple weeks ago to make sure nothing breaks:

https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/34054

I'm planning to give it another week or two for people to really get deep
into the review/testing before I start looking to merge. If you haven't
already, please check.


Thanks,
Mike