nir_opt_algebraic: Add a couple optimizations for lowered unpack(pack())HEADmain

I noticed some unnecessary 64-bit ints in shaders that were using doubles.
Perhaps there's a different missing optimization that should run on the
actual pack/unpack instructions before they're lowered, or maybe I'm just
lowering them too early, but these seem simple enough that we might want
them even for hand-rolled pack/unpack pairs.

Reviewed-by: Daniel Schürmann <daniel@schuermann.dev>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/27314>

0 files changed, 0 insertions, 0 deletions