Merge branch 'ps/reftable-drop-generic' into ps/reftable-concurrent-compaction

* ps/reftable-drop-generic: (24 commits) reftable/generic: drop interface t/helper: refactor to not use `struct reftable_table` t/helper: use `hash_to_hex_algop()` to print hashes t/helper: inline printing of reftable records t/helper: inline `reftable_table_print()` t/helper: inline `reftable_stack_print_directory()` t/helper: inline `reftable_reader_print_file()` t/helper: inline `reftable_dump_main()` reftable/dump: drop unused `compact_stack()` reftable/generic: move generic iterator code into iterator interface reftable/iter: drop double-checking logic reftable/stack: open-code reading refs reftable/merged: stop using generic tables in the merged table reftable/merged: rename `reftable_new_merged_table()` reftable/merged: expose functions to initialize iterators reftable/stack: handle locked tables during auto-compaction reftable/stack: fix corruption on concurrent compaction reftable/stack: use lock_file when adding table to "tables.list" reftable/stack: do not die when fsyncing lock file files reftable/stack: simplify tracking of table locks ...