Function query_feed 

pub(crate) fn query_feed<'tcx, Cache, Value>(
    tcx: TyCtxt<'tcx>,
    dep_kind: DepKind,
    hasher: Option<fn(&mut StableHashingContext<'_>, &Value) -> Fingerprint>,
    cache: &Cache,
    key: Cache::Key,
    erased: Erase<Value>,
)
where
    Cache: QueryCache<Value = Erase<Value>>,
    Cache::Key: DepNodeParams<TyCtxt<'tcx>>,
    Value: EraseType + Debug,

Common implementation of query feeding, used by define_feedable!.