Handle phis in two groups: first those which already have a preferred
reg set and then those without. The second group should be rare but by
handling them last, they don't accidentally occupy a preferred reg of
another phi, preventing excessive copying in some cases.
Signed-off-by: Job Noorman <jnoorman@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/33489>
Job Noorman
c6a932d4b3