radv/aco: enable 8/16-bit storage and int8/int16 on GFX8+

With this, Doom Eternal should now run with ACO on GFX8+.

The generated 8/16-bit storage code is okay but the generated int8/int16
code is currently pretty bad but it works and apparently Doom Eternal
doesn't actually use it (even though it requires it).

Signed-off-by: Rhys Perry <pendingchaos02@gmail.com>
Reviewed-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Part-of: <mesa/mesa!4707>
24 jobs for !4707 with aco_enable_8bit_16bit in 8 minutes and 52 seconds (queued for 3 seconds)
detached
Status Job ID Name Coverage
  Container
passed #2434960
aarch64
arm_build

00:00:20

passed #2434961
aarch64
arm_test

00:00:20

passed #2434962
windows shell 1809 mesa
windows_build_vs2019

00:00:09

passed #2434956
x86_build

00:00:21

passed #2434959
x86_build_old

00:00:23

passed #2434957
x86_test-gl

00:00:17

passed #2434958
x86_test-vk

00:00:23

 
  Meson X86 64
passed #2434966
meson-clang

00:04:33

passed #2434965
meson-classic

00:03:07

passed #2434967
meson-clover

00:04:04

passed #2434968
meson-clover-old-llvm

00:01:46

passed #2434964
meson-gallium

00:06:42

passed #2434963
meson-testing

00:02:08

passed #2434969
meson-vulkan

00:03:56

 
  Scons
passed #2434970
scons-win64

00:08:27

 
  Meson Misc
passed #2434972
aarch64
meson-arm64

00:01:51

passed #2434973
aarch64
meson-arm64-build-test

00:02:41

passed #2434971
aarch64
meson-armhf

00:02:20

passed #2434975
meson-i386

00:03:29

passed #2434978
meson-mingw32-x86_64

00:01:01

passed #2434977
kvm
meson-ppc64el

00:03:04

passed #2434976
kvm
meson-s390x

00:05:07

passed #2434974
windows docker 1809 mesa
meson-windows-vs2019

00:05:43

 
  Radv
passed #2434979
radv-fossils

00:00:33