17fd191eed
Vulkan allows fragment shaders to read gl_ClipDistance[], in which case the SPIR-V compiler inserts a single compact array variable for VARYING_SLOW_CLIP_DIST0 and the lowering should not try to inject its own variables, but instead work in terms of the existing one. Vulkan drivers are expected to call this with use_clipdist_array set to true to be consistent with this setup. Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com> Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6022>