message: Speed up compact
diff: @@ -727,11 +727,11 @@ bool Realm::compact()
  throw InvalidTransactionException("Can't compact a Realm within a write transaction");
  }
  - Group& group = read_group();
  - for (auto &object_schema : m_schema) {
  - ObjectStore::table_for_object_type(group, object_schema.name)->optimize();
  - }
  + verify_open();
  + // FIXME: when enum columns are ready, optimise all tables in a write transaction
  + if (m_group) {
  m_shared_group->end_read();
  + }
  m_group = nullptr;
  return m_shared_group->compact();
  