pan/bi: Generalize swizzles to avoid extracts

We'd really rather not emit extracts. We are approaching on a vector IR
anyway which is annoying but really necessary to handle I/O and fp16
correctly. So let's just go all the way and deal with swizzles and masks
within reason; it'll still be somewhat saner in the long-term.

Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4139>
3 files changed