this logic relies on constant indexing for compact arrays, but this is
frequently not the case for compact array builtins (e.g., gl_TessLevelOuter).
the usual strategy of lowering to temps isn't viable in TCS, which means
io lowering has to be able to handle indirect access to these builtins
without crashing
cc: mesa-stable
Reviewed-by: Dave Airlie <airlied@redhat.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/27534>
(cherry picked from commit 9e2c7314f2)
0675801f72