Function rustc_query_system::query::plumbing::try_get_cached

pub fn try_get_cached<Tcx, C>(
    tcx: Tcx,
    cache: &C,
    key: &C::Key,
) -> Option<C::Value>
where
    C: QueryCache,
    Tcx: DepContext,

Checks if the query is already computed and in the cache. It returns the shard index and a lock guard to the shard, which will be used if the query is not in the cache and we need to compute it.