Use new DocSet/Scorer API 💬 by Caio 5 years ago (log)
Introduced on tantivy.git @ e25284ba This changeset is sufficient, however upstream's f71b04acb introduced a `debug_assert!(self.doc() <= target)` for `SegmentPostings::seek` that looks overzealous to me. In release mode all tests pass, but given that lot has changed since last I looked I'll be double checking the affected functionality prior to letting this go wild.