etnaviv: nir: do a late nir_opt_cse run

What does this MR do and why?

etnaviv: nir: do a late nir_opt_cse run

This cleans up a lot and helps to generate much better code. There are only benefits on GPUs without inline immediate support.

shader-db results on GC2000:

total instructions in shared programs: 237168 -> 235101 (-0.87%)
instructions in affected programs: 17297 -> 15230 (-11.95%)
helped: 758
HURT: 0
helped stats (abs) min: 1 max: 24 x̄: 2.73 x̃: 2
helped stats (rel) min: 7.14% max: 29.41% x̄: 14.47% x̃: 14.29%
95% mean confidence interval for instructions value: -2.94 -2.51
95% mean confidence interval for instructions %-change: -14.84% -14.09%
Instructions are helped.

total temps in shared programs: 85553 -> 84969 (-0.68%)
temps in affected programs: 2879 -> 2295 (-20.28%)
helped: 584
HURT: 0
helped stats (abs) min: 1 max: 1 x̄: 1.00 x̃: 1
helped stats (rel) min: 5.00% max: 25.00% x̄: 21.48% x̃: 20.00%
95% mean confidence interval for temps value: -1.00 -1.00
95% mean confidence interval for temps %-change: -21.76% -21.21%
Temps are helped.

total immediates in shared programs: 154800 -> 154800 (0.00%)
immediates in affected programs: 0 -> 0
helped: 0
HURT: 0

total loops in shared programs: 0 -> 0
loops in affected programs: 0 -> 0
helped: 0
HURT: 0

LOST:   0
GAINED: 0

No changes on GC3000 and GC7000.

Signed-off-by: Christian Gmeiner cgmeiner@igalia.com