Function query_ensure_result 

pub(crate) fn query_ensure_result<'tcx, C, T>(
    tcx: TyCtxt<'tcx>,
    query: &'tcx QueryVTable<'tcx, C>,
    key: C::Key,
) -> Result<(), ErrorGuaranteed>
where
    C: QueryCache<Value = Erased<Result<T, ErrorGuaranteed>>>,
    Result<T, ErrorGuaranteed>: Erasable,

Implementation of tcx.ensure_result().$query(..) for queries that return Result<_, ErrorGuaranteed>.