tests: Add some clip/cull distance tests.

Eventually I also plan to add tests that use the tessellator. Unfortunately some tests in this file (actually, any tests that uses cull distances, apparently) crashes the Windows AMD driver on the Steam Deck, so that's not a viable platform for writing these tests. Also, I had written some negative tests too, but they crash DXCompiler on Linux (see https://github.com/microsoft/DirectXShaderCompiler/issues/6964, but I don't know whether it'll ever get some attention), so I'm not submitting them. They are here: giomasce/vkd3d@c7f3fdbe. The only way I can think we could meaningfully keep them in our test suite (and I think they are valuable, especially for our HLSL compiler) is adding another [require] flag to skip DXC on Linux.