This previously worked by luck because we were incorrectly calling
nir_opt_remove_phis before calling nir_convert_from_ssa. See also #10727.
No shader-db or fossil-db changes on any Intel platform.
v2: Handle the load_interpolated_input and load_barycentric_at_sample as
separate passes. Based on discussion with Ken starting at
https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/28136#note_2330424.
Fixes: 74a40cc4b6 ("intel/fs: move lower of non-uniform at_sample barycentric to NIR")
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/28136>
87101e7d83