aco: use v_xor3_b32
fossil-db (Navi):
Totals from 334 (0.26% of 128321) affected shaders:
CodeSize: 3345532 -> 3345484 (-0.00%); split: -0.00%, +0.00%
Instrs: 624662 -> 622778 (-0.30%); split: -0.30%, +0.00%
Mostly affects some parallel-rdp shaders