b312155cc5
It turns out that the hardware automatically selects whether PrimID passthrough needs to happen based on whether GS is enabled, which means that it's safe to always set these registers based whether PrimID is read by the FS and the hardware will ignore them when GS is enabled. Use the real names for these registers to make it less confusing when we start to do that. Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/25076>