[PATCH 0/1] MR231: vkd3d-shader/spirv: Retrieve input sysvals from the signature for geometry shaders as well.

[Zebediah Figura (＠zfigura)]

This only affects clip and cull distances. The HLSL compiler emits these using
dcl_input, but the previous shader (vertex or TES) will write them as a SPIRV
builtin, and hence we want to read this as a SPIRV builtin as well.

This fixes validation errors in Wine's test_clip_distance().