Using ok() may result in todo's succeeding when create_shader_stage()
succeeds, but vkCreateGraphicsPipelines() fails. There's not much point
in using ok() here in the first place though, because ultimately the
draw operation is going to fail when shader compilation failed.
Most Vulkan drivers are happy to compile a pipeline with interstage
interface mismatches, even if the pipeline will be broken. Metal,
and therefore MoltenVK, instead doesn't and errors out immediately.
This allows the Vulkan runner to execute in environments which do
not support geometry shaders, most notably MoltenVK. In particular,
that enables SM<4 shaders to run in such environments
The used UAV formats are explicitly added in the [require] section of
every test that uses them.
Some of these tests were failing on Intel UHD graphics 770 because of
missing support for additional UAV load types, explicitly requiring
these formats allows these tests to be skipped.
