Replace occurrences of InvalidXid with InvalidTransactionId

While Xid is a known shortening of TransactionId, InvalidXid is not
defined in the code. Fix comments which mistakenly were using the
shorter version.

Author: Bharath Rupireddy <[email protected]>
Discussion: https://postgr.es/m/CALj2ACUQzdigML868nV4cojfELPkEzNLNOk7b91Pho4JB90fng@mail.gmail.com

Author: danielgustafsson

src/backend/access/heap/heapam.c

@@ -3589,9 +3589,9 @@ heap_update(Relation relation, ItemPointer otid, HeapTuple newtup,
 	/*
 	 * And also prepare an Xmax value for the new copy of the tuple.  If there
 	 * was no xmax previously, or there was one but all lockers are now gone,
-	 * then use InvalidXid; otherwise, get the xmax from the old tuple.  (In
-	 * rare cases that might also be InvalidXid and yet not have the
-	 * HEAP_XMAX_INVALID bit set; that's fine.)
+	 * then use InvalidTransactionId; otherwise, get the xmax from the old
+	 * tuple.  (In rare cases that might also be InvalidTransactionId and yet
+	 * not have the HEAP_XMAX_INVALID bit set; that's fine.)
 	 */
 	if ((oldtup.t_data->t_infomask & HEAP_XMAX_INVALID) ||
 		HEAP_LOCKED_UPGRADED(oldtup.t_data->t_infomask) ||

src/backend/utils/time/snapmgr.c

@@ -919,9 +919,9 @@ xmin_cmp(const pairingheap_node *a, const pairingheap_node *b, void *arg)
 /*
  * SnapshotResetXmin
  *
- * If there are no more snapshots, we can reset our PGPROC->xmin to InvalidXid.
- * Note we can do this without locking because we assume that storing an Xid
- * is atomic.
+ * If there are no more snapshots, we can reset our PGPROC->xmin to
+ * InvalidTransactionId. Note we can do this without locking because we assume
+ * that storing an Xid is atomic.
  *
  * Even if there are some remaining snapshots, we may be able to advance our
  * PGPROC->xmin to some degree.  This typically happens when a portal is