The last major feature for compute shader support.
The tests are a bit ad-hoc, and ideally would be extended beyond d3d12. The nonuniform readback is what makes this difficult.
My plan is to refactor the shader runner so that it exposes an interface usable both from a file interpreter frontend and also directly from C code. That would allow, in this case, declaring the shaders and drawing as a shader_test file would, but then making use of C loops to test the readback. It would also make it generally easier to port loop-based tests in e.g. d3d12.c.