Now that register spilling is in place, this is reasonable. It turns out
for some shaders, it's actually better to cap at 8 work registers and
extra >8 uniform reigsters and tolerate the spilling, since the extra
resulting threads make up for the spillage. So incidentally, the shader
that spills here is in -bterrain, which jumps from 19fps to 21fps as a
result of this change.

total instructions in shared programs: 3513 -> 3448 (-1.85%)
instructions in affected programs: 776 -> 711 (-8.38%)
helped: 20
HURT: 0
helped stats (abs) min: 1 max: 8 x̄: 3.25 x̃: 2
helped stats (rel) min: 3.57% max: 16.00% x̄: 8.37% x̃: 7.19%
95% mean confidence interval for instructions value: -4.28 -2.22
95% mean confidence interval for instructions %-change: -10.02% -6.73%
Instructions are helped.

total bundles in shared programs: 2067 -> 2024 (-2.08%)
bundles in affected programs: 515 -> 472 (-8.35%)
helped: 19
HURT: 1
helped stats (abs) min: 1 max: 6 x̄: 2.37 x̃: 2
helped stats (rel) min: 2.13% max: 17.86% x̄: 10.19% x̃: 11.11%
HURT stats (abs)   min: 2 max: 2 x̄: 2.00 x̃: 2
HURT stats (rel)   min: 3.23% max: 3.23% x̄: 3.23% x̃: 3.23%
95% mean confidence interval for bundles value: -3.01 -1.29
95% mean confidence interval for bundles %-change: -12.13% -6.91%
Bundles are helped.

total quadwords in shared programs: 3468 -> 3426 (-1.21%)
quadwords in affected programs: 764 -> 722 (-5.50%)
helped: 19
HURT: 1
helped stats (abs) min: 1 max: 5 x̄: 2.26 x̃: 2
helped stats (rel) min: 1.41% max: 12.50% x̄: 6.76% x̃: 7.14%
HURT stats (abs)   min: 1 max: 1 x̄: 1.00 x̃: 1
HURT stats (rel)   min: 1.08% max: 1.08% x̄: 1.08% x̃: 1.08%
95% mean confidence interval for quadwords value: -2.83 -1.37
95% mean confidence interval for quadwords %-change: -8.08% -4.65%
Quadwords are helped.

total registers in shared programs: 383 -> 360 (-6.01%)
registers in affected programs: 112 -> 89 (-20.54%)
helped: 19
HURT: 0
helped stats (abs) min: 1 max: 3 x̄: 1.21 x̃: 1
helped stats (rel) min: 12.50% max: 27.27% x̄: 20.63% x̃: 20.00%
95% mean confidence interval for registers value: -1.47 -0.95
95% mean confidence interval for registers %-change: -22.39% -18.87%
Registers are helped.

total threads in shared programs: 432 -> 451 (4.40%)
threads in affected programs: 19 -> 38 (100.00%)
helped: 11
HURT: 0
helped stats (abs) min: 1 max: 2 x̄: 1.73 x̃: 2
helped stats (rel) min: 100.00% max: 100.00% x̄: 100.00% x̃: 100.00%
95% mean confidence interval for threads value: 1.41 2.04
95% mean confidence interval for threads %-change: 100.00% 100.00%
Threads are [helped].

total loops in shared programs: 4 -> 4 (0.00%)
loops in affected programs: 0 -> 0
helped: 0
HURT: 0

total spills in shared programs: 0 -> 4
spills in affected programs: 0 -> 4
helped: 0
HURT: 2

total fills in shared programs: 0 -> 7
fills in affected programs: 0 -> 7
helped: 0
HURT: 2

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