This was added for no good reason by
c91560defc57, after
b7eda3e0e334
had just moved the prototype from utils/tqual.h to utils/snapmgr.h.
Author: Japin Li <japinli@hotmail.com>
Discussion: https://postgr.es/m/MEYP282MB16693A409F3282A9DB287BADB63E9@MEYP282MB1669.AUSP282.PROD.OUTLOOK.COM
extern void HeapTupleSetHintBits(HeapTupleHeader tuple, Buffer buffer,
uint16 infomask, TransactionId xid);
extern bool HeapTupleHeaderIsOnlyLocked(HeapTupleHeader tuple);
-extern bool XidInMVCCSnapshot(TransactionId xid, Snapshot snapshot);
extern bool HeapTupleIsSurelyDead(HeapTuple htup,
struct GlobalVisState *vistest);