radeonsi: skip vs output optimizations for some outputs

If PT_SPRITE_TEX is enabled, PS inputs are overriden at runtime so
we can't apply the vs output optim.

Closes: https://gitlab.freedesktop.org/mesa/mesa/-/issues/2747
Fixes: 3ec9975555 ("radeonsi: eliminate trivial constant VS outputs")
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4559>

src/amd/llvm/ac_llvm_build.h

@@ -611,6 +611,7 @@ void ac_optimize_vs_outputs(struct ac_llvm_context *ac,
 			    LLVMValueRef main_fn,
 			    uint8_t *vs_output_param_offset,
 			    uint32_t num_outputs,
+			    uint32_t skip_output_mask,
 			    uint8_t *num_param_exports);
 void ac_init_exec_full_mask(struct ac_llvm_context *ctx);