If shared RA is used, it may have handled some phis. These are already
ignored by regular RA in handle_phi but were used before that in
potentially dangerous ways. More specifically, the interval of such phis
was accessed which may cause an out-of-bounds read since it was never
created. Fix this by skipping such phis earlier.
Signed-off-by: Job Noorman <jnoorman@igalia.com>
Fixes: c6a932d4b3 ("ir3/ra: handle phis with preferred regs first")
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/34503>
af8105d085