ReplicationSlotCtl: undefined reference

Greetings.

Trying to build pg extension I've got error:
```
pglogical_monitoring.o:pglogical_monitoring.c:(.rdata$.refptr.ReplicationSlotCtl[.refptr.ReplicationSlotCtl]+0x0):
undefinedreference to `ReplicationSlotCtl'
 
collect2: error: ld returned 1 exit status
```

But according to https://commitfest.postgresql.org/16/1390/ it should
be marked with PGDLLIMPORT.

However checking sources there is no this spec

(https://github.com/postgres/postgres/blob/fff2a7d7bd09db38e1bafc1303c29b10a9805dc0/src/include/replication/slot.h#L172):

```
extern ReplicationSlotCtlData *ReplicationSlotCtl;
```

Am I correct or missing smth?
Craig, it supposed to be your proposal about ReplicationSlotCtl and
patch. Am I right?

-- 
Kind regards,
 Pavlo                          mailto:pavlo.golub@cybertec.at