nir/algebraic: propagate b2i out of ior/iand

nir/algebraic: propagate b2i out of ior/iand

Totals from 761 (0.57% of 134368) affected shaders (Polaris):
SGPRs: 29496 -> 29488 (-0.03%)
SpillSGPRs: 41 -> 43 (+4.88%)
CodeSize: 1922036 -> 1882408 (-2.06%); split: -2.08%, +0.02%
Instrs: 366051 -> 360362 (-1.55%); split: -1.57%, +0.02%
Cycles: 7692516 -> 7661216 (-0.41%); split: -0.41%, +0.01%
VMEM: 365175 -> 365172 (-0.00%)
VClause: 15324 -> 15322 (-0.01%)
SClause: 9825 -> 9824 (-0.01%); split: -0.02%, +0.01%
Copies: 41216 -> 41294 (+0.19%); split: -0.01%, +0.20%
Branches: 7020 -> 7033 (+0.19%)
PreSGPRs: 22103 -> 22106 (+0.01%)
PreVGPRs: 26518 -> 26515 (-0.01%)

Reviewed-by: Rhys Perry <pendingchaos02@gmail.com>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4830>