fn fn_abi_of_fn_ptr<'tcx>( tcx: TyCtxt<'tcx>, query: ParamEnvAnd<'tcx, (PolyFnSig<'tcx>, &'tcx List<Ty<'tcx>>)>) -> Result<&'tcx FnAbi<'tcx, Ty<'tcx>>, FnAbiError<'tcx>>