broadcom/compiler: improve generation of if conditions

Where it is safe to do so, avoid the generation of code to convert a
condition code into a boolean which is then tested to generate a
condition code. This is only done in uniform ifs, and only for condition
values that are SSA and only used once (in that if statement).
39 jobs for !8709 with review/better-ifs in 14 seconds (queued for 2 seconds)
detached
Status Job ID Name Coverage
  Sanity
passed #6883161
sanity

00:00:14

 
  Container
manual #6883164
aarch64 manual
arm_build
manual #6883165
manual
arm_test-base
manual #6883166
windows shell 1809 mesa manual
windows_build_vs2019
manual #6883162
manual
x86_build-base
manual #6883163
manual
x86_test-base
 
  Container 2
created #6883174
android_build
created #6883177
arm64_test
created #6883178
armhf_test
created #6883171
i386_build
created #6883167
kernel+rootfs_amd64
created #6883168
aarch64
kernel+rootfs_arm64
created #6883169
aarch64
kernel+rootfs_armhf
created #6883172
ppc64el_build
created #6883173
s390x_build
created #6883170
x86_build
created #6883175
x86_test-gl
created #6883176
x86_test-vk
 
  Meson X86 64
created #6883184
meson-clang
created #6883185
meson-clover
created #6883181
meson-clover-testing
created #6883182
meson-gallium
created #6883183
meson-release
created #6883179
meson-testing
created #6883180
meson-testing-asan
created #6883186
meson-vulkan
 
  Build Misc
created #6883187
meson-android
created #6883189
aarch64
meson-arm64
created #6883190
aarch64
meson-arm64-build-test
created #6883188
aarch64
meson-armhf
created #6883192
meson-i386
created #6883195
meson-mingw32-x86_64
created #6883194
kvm
meson-ppc64el
created #6883193
kvm
meson-s390x
created #6883191
allowed to fail
scons-win64
 
  Raspberrypi
created #6883196
igalia-rpi3
vc4-rpi3-gles2:armhf 1/4
created #6883197
igalia-rpi3
vc4-rpi3-gles2:armhf 2/4
created #6883198
igalia-rpi3
vc4-rpi3-gles2:armhf 3/4
created #6883199
igalia-rpi3
vc4-rpi3-gles2:armhf 4/4