message: Release slab as soon as possible after commit
diff: @@ -1794,6 +1794,11 @@ SharedGroup::version_type SharedGroup::commit()
  release_read_lock(lock_after_commit);
  do_end_write();
  +
  + // Free memory that was allocated during the write transaction.
  + using gf = _impl::GroupFriend;
  + gf::reset_free_space_tracking(m_group); // Throws
  +
  do_end_read();
  m_read_lock = lock_after_commit;
  m_transact_stage = transact_Ready;
  