Re: Enumize logical replication message actions

Those two switch()es are apparently redundant. That code is exactly
equivalent to:

apply_dispatch(s)
{
  LogicalRepMsgType msgtype = pq_getmsgtype(s);

  switch (msgtype)
  {
     case LOGICAL_REP_MSG_BEGIN:
        apply_handle_begin();
!       return;
     ...
     case LOGICAL_REP_MSG_STREAM_COMMIT:
        apply_handle_begin();
!       return;
  }

  ereport(ERROR, (errmsg("invalid logical replication message type"..
}     

which is smaller and fast.