This is one step towards lowering I/O during shader preprocess rather than at variant create time, which helps mitigate shader variant jank. It's also a lot simpler.
This is important for Asahi (which needs to do variants based on blend state), but it's also a nice simplification to Panfrost and gets rid of nir_variable gunk.
Signed-off-by: Alyssa Rosenzweig alyssa@rosenzweig.io Signed-off-by: Alyssa Rosenzweig alyssa@collabora.com