Use more consistently int64 for page numbers in SLRU-related code

clog.c, async.c and predicate.c included some SLRU page numbers still
handled as 4-byte integers, while int64 should be used for this purpose.

These holes have been introduced in 4ed8f0913b, that has introduced
the use of 8-byte integers for SLRU page numbers, still forgot about the
code paths updated by this commit.

Reported-by: Noah Misch
Author: Aleksander Alekseev, Michael Paquier
Discussion: https://postgr.es/m/20240626002747.dc.nmisch@google.com
Backpatch-through: 17

src/backend/access/transam/clog.c

@@ -445,7 +445,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status,
 	PGPROC	   *proc = MyProc;
 	uint32		nextidx;
 	uint32		wakeidx;
-	int			prevpageno;
+	int64		prevpageno;
 	LWLock	   *prevlock = NULL;
 
 	/* We should definitely have an XID whose status needs to be updated. */
@@ -577,7 +577,7 @@ TransactionGroupUpdateXidStatus(TransactionId xid, XidStatus status,
 	while (nextidx != INVALID_PROC_NUMBER)
 	{
 		PGPROC	   *nextproc = &ProcGlobal->allProcs[nextidx];
-		int			thispageno = nextproc->clogGroupMemberPage;
+		int64		thispageno = nextproc->clogGroupMemberPage;
 
 		/*
 		 * If the page to update belongs to a different bank than the previous

src/backend/commands/async.c

@@ -283,7 +283,7 @@ typedef struct AsyncQueueControl
 	QueuePosition head;			/* head points to the next free location */
 	QueuePosition tail;			/* tail must be <= the queue position of every
 								 * listening backend */
-	int			stopPage;		/* oldest unrecycled page; must be <=
+	int64		stopPage;		/* oldest unrecycled page; must be <=
 								 * tail.page */
 	ProcNumber	firstListener;	/* id of first listener, or
 								 * INVALID_PROC_NUMBER */
@@ -1271,9 +1271,9 @@ asyncQueueUnregister(void)
 static bool
 asyncQueueIsFull(void)
 {
-	int			headPage = QUEUE_POS_PAGE(QUEUE_HEAD);
-	int			tailPage = QUEUE_POS_PAGE(QUEUE_TAIL);
-	int			occupied = headPage - tailPage;
+	int64		headPage = QUEUE_POS_PAGE(QUEUE_HEAD);
+	int64		tailPage = QUEUE_POS_PAGE(QUEUE_TAIL);
+	int64		occupied = headPage - tailPage;
 
 	return occupied >= max_notify_queue_pages;
 }
@@ -1505,9 +1505,9 @@ pg_notification_queue_usage(PG_FUNCTION_ARGS)
 static double
 asyncQueueUsage(void)
 {
-	int			headPage = QUEUE_POS_PAGE(QUEUE_HEAD);
-	int			tailPage = QUEUE_POS_PAGE(QUEUE_TAIL);
-	int			occupied = headPage - tailPage;
+	int64		headPage = QUEUE_POS_PAGE(QUEUE_HEAD);
+	int64		tailPage = QUEUE_POS_PAGE(QUEUE_TAIL);
+	int64		occupied = headPage - tailPage;
 
 	if (occupied == 0)
 		return (double) 0;		/* fast exit for common case */
@@ -1932,7 +1932,7 @@ asyncQueueReadAllNotifications(void)
 
 		do
 		{
-			int			curpage = QUEUE_POS_PAGE(pos);
+			int64		curpage = QUEUE_POS_PAGE(pos);
 			int			curoffset = QUEUE_POS_OFFSET(pos);
 			int			slotno;
 			int			copysize;
@@ -2108,9 +2108,9 @@ static void
 asyncQueueAdvanceTail(void)
 {
 	QueuePosition min;
-	int			oldtailpage;
-	int			newtailpage;
-	int			boundary;
+	int64		oldtailpage;
+	int64		newtailpage;
+	int64		boundary;
 
 	/* Restrict task to one backend per cluster; see SimpleLruTruncate(). */
 	LWLockAcquire(NotifyQueueTailLock, LW_EXCLUSIVE);

src/backend/storage/lmgr/predicate.c

@@ -344,7 +344,7 @@ static SlruCtlData SerialSlruCtlData;
 
 typedef struct SerialControlData
 {
-	int			headPage;		/* newest initialized page */
+	int64		headPage;		/* newest initialized page */
 	TransactionId headXid;		/* newest valid Xid in the SLRU */
 	TransactionId tailXid;		/* oldest xmin we might be interested in */
 }			SerialControlData;
@@ -1035,7 +1035,7 @@ SerialSetActiveSerXmin(TransactionId xid)
 void
 CheckPointPredicate(void)
 {
-	int			truncateCutoffPage;
+	int64		truncateCutoffPage;
 
 	LWLockAcquire(SerialControlLock, LW_EXCLUSIVE);
 
@@ -1048,7 +1048,7 @@ CheckPointPredicate(void)
 
 	if (TransactionIdIsValid(serialControl->tailXid))
 	{
-		int			tailPage;
+		int64		tailPage;
 
 		tailPage = SerialPage(serialControl->tailXid);