message: Add MemberListSyncer.isRemoteJoinedToRoom
diff: @@ -43,6 +43,14 @@ function MemberListSyncer(ircBridge, appServiceBot, server, appServiceUserId, in
  this._leaveQueuePool = new QueuePool(3, this._leaveUsersInRoom.bind(this));
  }
  +MemberListSyncer.prototype.isRemoteJoinedToRoom = Promise.coroutine(function*(roomId, userId) {
  + const room = this._memberLists.matrix[roomId];
  + if (room !== undefined) {
  + return room.remoteJoinedUsers.includes(userId);
  + }
  + return false;
  +});
  +
  MemberListSyncer.prototype.sync = Promise.coroutine(function*() {
  let server = this.server;
  if (!server.isMembershipListsEnabled()) {
  