fn relate_mir_and_user_args<'tcx>(
    ocx: &ObligationCtxt<'_, 'tcx>,
    param_env: ParamEnv<'tcx>,
    span: Span,
    mir_ty: Ty<'tcx>,
    def_id: DefId,
    user_args: UserArgs<'tcx>,
) -> Result<(), NoSolution>