84da4ded4b
Otherwise the ctx.ac.postponed_kill will not be allocated.
Fixes: ce87da71e9 ("nir: add pass to lower discard() to demote()")
Closes: https://gitlab.freedesktop.org/mesa/mesa/issues/2662
Reviewed-by: Daniel Schürmann <daniel@schuermann.dev>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4301>