With tests from !364, separated out from the HLSL changes there and updated.
It is apparently unnecessary to match the SM4/5 implementation, since the AMD Windows results differ. The RADV results are a bit wrong, but Proton uses the SPIR-V GLSL extension instructions too, and no workarounds have been implemented there.
-- v3: vkd3d-shader/spirv: Handle the ACOS, ASIN and ATAN instructions in spirv_compiler_emit_ext_glsl_instruction(). vkd3d-shader/dxil: Handle inverse trigonometric functions in sm6_parser_emit_dx_unary(). tests/shader-runner: Add tests for atan and atan2 trig intrinsics. tests/shader-runner: Add tests for acos and asin trig intrinsics.