aco: implement b2i8/b2i16

Fixes lots of tests under dEQP-VK.spirv_assembly.type.*

Signed-off-by: Rhys Perry <pendingchaos02@gmail.com>
Reviewed-by: Daniel Schürmann <daniel@schuermann.dev>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5993>
2 files changed