radv, nir: remove nir_opt_reuse_constants
Based on !31028 to avoid some stats regressions.
aco now rematerializes constants per block, so this nir pass no longer does anything meaningful besides adding noise:
Foz-DB Navi31:
Totals from 4674 (5.89% of 79395) affected shaders:
Instrs: 11497431 -> 11497335 (-0.00%); split: -0.02%, +0.02%
CodeSize: 60720620 -> 60725904 (+0.01%); split: -0.02%, +0.03%
VGPRs: 294440 -> 294428 (-0.00%)
SpillSGPRs: 3486 -> 3488 (+0.06%); split: -0.06%, +0.11%
Latency: 109298610 -> 109319617 (+0.02%); split: -0.02%, +0.04%
InvThroughput: 18606377 -> 18640872 (+0.19%); split: -0.01%, +0.19%
VClause: 232602 -> 232622 (+0.01%); split: -0.00%, +0.01%
SClause: 299675 -> 299746 (+0.02%); split: -0.01%, +0.04%
Copies: 840683 -> 840105 (-0.07%); split: -0.14%, +0.07%
Branches: 304581 -> 304646 (+0.02%); split: -0.00%, +0.03%
PreSGPRs: 233651 -> 233611 (-0.02%); split: -0.02%, +0.00%
VALU: 6624760 -> 6625051 (+0.00%); split: -0.00%, +0.01%
SALU: 1236841 -> 1236103 (-0.06%); split: -0.12%, +0.06%
VOPD: 2993 -> 2970 (-0.77%); split: +0.17%, -0.94%