Instead of ingesting 1-bit booleans and trying to force everything to be
16-bit, except when it isn't, and creating a mess in the backend... just
use the NIR pass designed to select bitsize for booleans. Yes, this
means we need to handle more NIR instructions, but the handling is
easier and the conversion is more obvious (except for some edge cases
like 16-bit vectorized b32csel). This generates noticeably better code,
and the generated code will be easier to optimize.

total instructions in shared programs: 90257 -> 88941 (-1.46%)
instructions in affected programs: 49145 -> 47829 (-2.68%)
helped: 201
HURT: 2
helped stats (abs) min: 1.0 max: 40.0 x̄: 6.57 x̃: 3
helped stats (rel) min: 0.29% max: 13.89% x̄: 2.57% x̃: 1.90%
HURT stats (abs)   min: 2.0 max: 2.0 x̄: 2.00 x̃: 2
HURT stats (rel)   min: 2.15% max: 2.74% x̄: 2.45% x̃: 2.45%
95% mean confidence interval for instructions value: -7.71 -5.26
95% mean confidence interval for instructions %-change: -2.84% -2.20%
Instructions are helped.

total tuples in shared programs: 73740 -> 72922 (-1.11%)
tuples in affected programs: 36564 -> 35746 (-2.24%)
helped: 184
HURT: 7
helped stats (abs) min: 1.0 max: 74.0 x̄: 4.49 x̃: 2
helped stats (rel) min: 0.30% max: 16.67% x̄: 2.86% x̃: 1.89%
HURT stats (abs)   min: 1.0 max: 2.0 x̄: 1.29 x̃: 1
HURT stats (rel)   min: 0.12% max: 12.50% x̄: 4.26% x̃: 3.33%
95% mean confidence interval for tuples value: -5.29 -3.28
95% mean confidence interval for tuples %-change: -3.06% -2.13%
Tuples are helped.

total clauses in shared programs: 15993 -> 15928 (-0.41%)
clauses in affected programs: 2464 -> 2399 (-2.64%)
helped: 35
HURT: 16
helped stats (abs) min: 1.0 max: 27.0 x̄: 2.31 x̃: 1
helped stats (rel) min: 0.49% max: 18.88% x̄: 7.63% x̃: 5.88%
HURT stats (abs)   min: 1.0 max: 1.0 x̄: 1.00 x̃: 1
HURT stats (rel)   min: 0.79% max: 6.25% x̄: 1.91% x̃: 1.01%
95% mean confidence interval for clauses value: -2.46 -0.09
95% mean confidence interval for clauses %-change: -6.38% -2.90%
Clauses are helped.

total cycles in shared programs: 7622.13 -> 7594.75 (-0.36%)
cycles in affected programs: 1078.67 -> 1051.29 (-2.54%)
helped: 103
HURT: 4
helped stats (abs) min: 0.041665999999999315 max: 3.0833319999999986 x̄: 0.27 x̃: 0
helped stats (rel) min: 0.32% max: 21.05% x̄: 3.62% x̃: 2.44%
HURT stats (abs)   min: 0.0416669999999999 max: 0.0833330000000001 x̄: 0.05 x̃: 0
HURT stats (rel)   min: 0.13% max: 7.14% x̄: 2.94% x̃: 2.25%
95% mean confidence interval for cycles value: -0.33 -0.19
95% mean confidence interval for cycles %-change: -4.14% -2.61%
Cycles are helped.

total arith in shared programs: 2762.46 -> 2728.08 (-1.24%)
arith in affected programs: 1550.12 -> 1515.75 (-2.22%)
helped: 197
HURT: 6
helped stats (abs) min: 0.041665999999999315 max: 3.0833319999999986 x̄: 0.18 x̃: 0
helped stats (rel) min: 0.32% max: 21.05% x̄: 2.93% x̃: 1.61%
HURT stats (abs)   min: 0.0416669999999999 max: 0.0833330000000001 x̄: 0.06 x̃: 0
HURT stats (rel)   min: 0.13% max: 20.00% x̄: 5.78% x̃: 3.37%
95% mean confidence interval for arith value: -0.21 -0.13
95% mean confidence interval for arith %-change: -3.20% -2.15%
Arith are helped.

total quadwords in shared programs: 68155 -> 67555 (-0.88%)
quadwords in affected programs: 27944 -> 27344 (-2.15%)
helped: 151
HURT: 9
helped stats (abs) min: 1.0 max: 52.0 x̄: 4.09 x̃: 3
helped stats (rel) min: 0.23% max: 12.35% x̄: 2.87% x̃: 2.17%
HURT stats (abs)   min: 1.0 max: 5.0 x̄: 1.89 x̃: 1
HURT stats (rel)   min: 0.20% max: 6.76% x̄: 1.91% x̃: 1.13%
95% mean confidence interval for quadwords value: -4.67 -2.83
95% mean confidence interval for quadwords %-change: -2.99% -2.21%
Quadwords are helped.

total threads in shared programs: 2232 -> 2233 (0.04%)
threads in affected programs: 1 -> 2 (100.00%)
helped: 1
HURT: 0

Signed-off-by: Alyssa Rosenzweig <alyssa@collabora.com>