pan/bi: Specialize shaders for IDVS

pan/bi: Specialize shaders for IDVS

We need to compile multiple variants and report them together in a
common shader info. To do so, we split off per-variant shader infos and
combine at the end.

glmark2 is very happy: https://people.collabora.com/~alyssa/idvs-g52.txt
Highlights include -bshading up 41% fps and -bbump:bump-render=high-poly
up 62% faster

Signed-off-by: Alyssa Rosenzweig <alyssa@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/14154>