nir/algebraic: Rearrange bcsel sequences generated by nir_opt_peephole_select

nir/algebraic: Rearrange bcsel sequences generated by nir_opt_peephole_select

Reviewed-by: Matt Turner <mattst88@gmail.com>
All Intel platforms had similar results. (Ice Lake shown)
total instructions in shared programs: 14660366 -> 14653437 (-0.05%)
instructions in affected programs: 316166 -> 309237 (-2.19%)
helped: 905
HURT: 10
helped stats (abs) min: 1 max: 36 x̄: 7.67 x̃: 6
helped stats (rel) min: 0.13% max: 18.75% x̄: 4.28% x̃: 3.60%
HURT stats (abs)   min: 1 max: 1 x̄: 1.00 x̃: 1
HURT stats (rel)   min: 0.10% max: 1.33% x̄: 0.70% x̃: 0.97%
95% mean confidence interval for instructions value: -7.91 -7.23
95% mean confidence interval for instructions %-change: -4.46% -3.99%
Instructions are helped.

total cycles in shared programs: 228571646 -> 228549759 (<.01%)
cycles in affected programs: 56239919 -> 56218032 (-0.04%)
helped: 681
HURT: 216
helped stats (abs) min: 1 max: 5156 x̄: 45.49 x̃: 10
helped stats (rel) min: <.01% max: 10.45% x̄: 1.29% x̃: 0.65%
HURT stats (abs)   min: 1 max: 320 x̄: 42.09 x̃: 14
HURT stats (rel)   min: <.01% max: 37.04% x̄: 1.38% x̃: 0.49%
95% mean confidence interval for cycles value: -41.51 -7.29
95% mean confidence interval for cycles %-change: -0.80% -0.49%
Cycles are helped.

LOST:   1
GAINED: 0