{"ast_node_type":"variable","tokens":[{"end":91,"kind":"keyword","start":0,"text":"let"}]}
            let (encode_const, encode_opt) = should_encode_mir(tcx, reachable_set, def_id);
        let keys_and_jobs = tcx.mir_keys(()).iter().filter_map(|&def_id| {
            if encode_const || encode_opt { Some((def_id, encode_const, encode_opt)) } else { None }