Count contrib/bloom index scans in pgstat view.

Maintain the pg_stat_user_indexes.idx_scan pgstat counter during
contrib/Bloom index scans.

Oversight in commit 9ee014f, which added the Bloom index contrib
module.

Author: Masahiro Ikeda <[email protected]>
Reviewed-By: Peter Geoghegan <[email protected]>
Discussion: https://postgr.es/m/[email protected]
Backpatch: 13- (all supported branches).

Author: petergeoghegan

contrib/bloom/blscan.c

@@ -15,6 +15,7 @@
 #include "access/relscan.h"
 #include "bloom.h"
 #include "miscadmin.h"
+#include "pgstat.h"
 #include "storage/bufmgr.h"
 
 /*
@@ -114,6 +115,7 @@ blgetbitmap(IndexScanDesc scan, TIDBitmap *tbm)
 	 */
 	bas = GetAccessStrategy(BAS_BULKREAD);
 	npages = RelationGetNumberOfBlocks(scan->indexRelation);
+	pgstat_count_index_scan(scan->indexRelation);
 
 	for (blkno = BLOOM_HEAD_BLKNO; blkno < npages; blkno++)
 	{