Function fn_abi_of_fn_ptr

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>>, &'tcx FnAbiError<'tcx>>