nir/algebraic: add floor + f2i/f2u patterns + add float_to_int_clamps + radeonsi/RADV changes
The first pattern occurs when emulating nearest filtering with clamp to edge. The nearest filter behavior floors, then converts to integer, and then applies clamping. The other two use a similar idea.
This adds a new compiler option float_to_int_clamps
to describe AMD GPU behavior. It also adds the corresponding constant expression evaluation changes.
Edited by Marek Olšák