Added:
* a pass that renumbers bases of IO intrinsics
* a pass that converts mediump IO to 16 bits, optionally using the new
packed varying slots
* a pass that sets (forces) mediump in IO intrinsics (for testing)
* a pass that remaps VARYING_SLOT_VAR[0..15]_16BIT to VARYING_SLOT_VAR[0..31]
(if some shader stages don't want packed varyings)
* a pass that folds type conversions around texture opcodes into those
opcodes (e.g. tex(f2f32(coord), ..) is changed into tex accepting f16)
* a pass that changes (legalizes) sampler src and dst types based on specified
hw constraints (e.g. derivatives must be the same type as coordinates)
Reviewed-by: Matt Turner <mattst88@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/9050>