This requires shader-side lowering, which is handled in dxil_nir_lower_vs_vertex_conversion(). Reviewed-by: Erik Faye-Lund <erik.faye-lund@collabora.com> Reviewed-by: Jesse Natalie <jenatali@microsoft.com> Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/15955>