Add is_analyze parameter to vacuum_delay_point().

This function is used in both vacuum and analyze code paths, and a
follow-up commit will require distinguishing between the two.  This
commit forces callers to specify whether they are in a vacuum or
analyze path, but it does not use that information for anything
yet.

Author: Nathan Bossart <nathandbossart@gmail.com>
Co-authored-by: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Discussion: https://postgr.es/m/ZmaXmWDL829fzAVX%40ip-10-97-1-34.eu-west-3.compute.internal

src/backend/access/gin/ginfast.c

@@ -892,7 +892,7 @@ ginInsertCleanup(GinState *ginstate, bool full_clean,
 		 */
 		processPendingPage(&accum, &datums, page, FirstOffsetNumber);
 
-		vacuum_delay_point();
+		vacuum_delay_point(false);
 
 		/*
 		 * Is it time to flush memory to disk?	Flush if we are at the end of
@@ -929,7 +929,7 @@ ginInsertCleanup(GinState *ginstate, bool full_clean,
 			{
 				ginEntryInsert(ginstate, attnum, key, category,
 							   list, nlist, NULL);
-				vacuum_delay_point();
+				vacuum_delay_point(false);
 			}
 
 			/*
@@ -1002,7 +1002,7 @@ ginInsertCleanup(GinState *ginstate, bool full_clean,
 		/*
 		 * Read next page in pending list
 		 */
-		vacuum_delay_point();
+		vacuum_delay_point(false);
 		buffer = ReadBuffer(index, blkno);
 		LockBuffer(buffer, GIN_SHARE);
 		page = BufferGetPage(buffer);

src/backend/access/gin/ginvacuum.c

@@ -662,12 +662,12 @@ ginbulkdelete(IndexVacuumInfo *info, IndexBulkDeleteResult *stats,
 			UnlockReleaseBuffer(buffer);
 		}
 
-		vacuum_delay_point();
+		vacuum_delay_point(false);
 
 		for (i = 0; i < nRoot; i++)
 		{
 			ginVacuumPostingTree(&gvs, rootOfPostingTree[i]);
-			vacuum_delay_point();
+			vacuum_delay_point(false);
 		}
 
 		if (blkno == InvalidBlockNumber)	/* rightmost page */
@@ -748,7 +748,7 @@ ginvacuumcleanup(IndexVacuumInfo *info, IndexBulkDeleteResult *stats)
 		Buffer		buffer;
 		Page		page;
 
-		vacuum_delay_point();
+		vacuum_delay_point(false);
 
 		buffer = ReadBufferExtended(index, MAIN_FORKNUM, blkno,
 									RBM_NORMAL, info->strategy);

src/backend/access/gist/gistvacuum.c

@@ -283,7 +283,7 @@ restart:
 	recurse_to = InvalidBlockNumber;
 
 	/* call vacuum_delay_point while not holding any buffer lock */
-	vacuum_delay_point();
+	vacuum_delay_point(false);
 
 	buffer = ReadBufferExtended(rel, MAIN_FORKNUM, blkno, RBM_NORMAL,
 								info->strategy);

src/backend/access/hash/hash.c

@@ -716,7 +716,7 @@ hashbucketcleanup(Relation rel, Bucket cur_bucket, Buffer bucket_buf,
 		bool		retain_pin = false;
 		bool		clear_dead_marking = false;
 
-		vacuum_delay_point();
+		vacuum_delay_point(false);
 
 		page = BufferGetPage(buf);
 		opaque = HashPageGetOpaque(page);

src/backend/access/heap/vacuumlazy.c

@@ -1214,7 +1214,7 @@ lazy_scan_heap(LVRelState *vacrel)
 		update_vacuum_error_info(vacrel, NULL, VACUUM_ERRCB_PHASE_SCAN_HEAP,
 								 blkno, InvalidOffsetNumber);
 
-		vacuum_delay_point();
+		vacuum_delay_point(false);
 
 		/*
 		 * Regularly check if wraparound failsafe should trigger.
@@ -2646,7 +2646,7 @@ lazy_vacuum_heap_rel(LVRelState *vacrel)
 		OffsetNumber offsets[MaxOffsetNumber];
 		int			num_offsets;
 
-		vacuum_delay_point();
+		vacuum_delay_point(false);
 
 		blkno = iter_result->blkno;
 		vacrel->blkno = blkno;

src/backend/access/nbtree/nbtree.c

@@ -1137,7 +1137,7 @@ backtrack:
 	backtrack_to = P_NONE;
 
 	/* call vacuum_delay_point while not holding any buffer lock */
-	vacuum_delay_point();
+	vacuum_delay_point(false);
 
 	/*
 	 * We can't use _bt_getbuf() here because it always applies

src/backend/access/spgist/spgvacuum.c

@@ -625,7 +625,7 @@ spgvacuumpage(spgBulkDeleteState *bds, BlockNumber blkno)
 	Page		page;
 
 	/* call vacuum_delay_point while not holding any buffer lock */
-	vacuum_delay_point();
+	vacuum_delay_point(false);
 
 	buffer = ReadBufferExtended(index, MAIN_FORKNUM, blkno,
 								RBM_NORMAL, bds->info->strategy);
@@ -704,7 +704,7 @@ spgprocesspending(spgBulkDeleteState *bds)
 			continue;			/* ignore already-done items */
 
 		/* call vacuum_delay_point while not holding any buffer lock */
-		vacuum_delay_point();
+		vacuum_delay_point(false);
 
 		/* examine the referenced page */
 		blkno = ItemPointerGetBlockNumber(&pitem->tid);