intel/compiler: Create and use struct for VS thread payload

Acked-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Marcin Ślusarz <marcin.slusarz@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Acked-by: Ian Romanick <ian.d.romanick@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/18176>

src/intel/compiler/brw_fs_thread_payload.cpp

@@ -25,6 +25,13 @@
 
 using namespace brw;
 
+vs_thread_payload::vs_thread_payload()
+{
+   urb_handles = retype(brw_vec8_grf(1, 0), BRW_REGISTER_TYPE_UD);
+
+   num_regs = 2;
+}
+
 tcs_thread_payload::tcs_thread_payload(const fs_visitor &v)
 {
    struct brw_vue_prog_data *vue_prog_data = brw_vue_prog_data(v.prog_data);