Make proof tree probing and `Candidate`/`CandidateSource` generic over interner `<TyCtxt<'tcx>>` is ugly, but will become `<I>` when things actually become generic. r? lcnr
Make proof tree probing and `Candidate`/`CandidateSource` generic over interner `<TyCtxt<'tcx>>` is ugly, but will become `<I>` when things actually become generic. r? lcnr