nir/lower_mediump: Fix metadata in all passes
Fixes: fb29cef8 ("nir: add many passes that lower and optimize 16-bit input/outputs and samplers") Signed-off-by:Alyssa Rosenzweig <alyssa@collabora.com> Reviewed-by:
Marek Olšák <marek.olsak@amd.com> Part-of: <mesa/mesa!11732>