PG-338: Fix counters regression test.

After fixing the problem with utility statements, this whole block:
do $$
declare
   n integer:= 1;
begin
	loop
		PERFORM a,b,c,d FROM t1, t2, t3, t4
			 WHERE t1.a = t2.b AND t3.c = t4.d ORDER BY a;
		exit when n = 1000;
		n := n + 1;
	end loop;
end $$;

Is only processed once, as those are nested statements, in order to
match the 1000 statements the GUC pg_stat_monitor.track must be set to
'all' and then back to the default of 'top' when done testing it.

regression/expected/counters.out

@@ -42,9 +42,16 @@ SELECT query,calls FROM pg_stat_monitor ORDER BY query COLLATE "C";
  SELECT pg_stat_monitor_reset()                                                  |     1
 (2 rows)
 
-SELECT pg_stat_monitor_reset();
+ALTER SYSTEM SET pg_stat_monitor.track TO 'all';
- pg_stat_monitor_reset 
+SELECT pg_reload_conf();
------------------------
+ pg_reload_conf 
+----------------
+ t
+(1 row)
+
+SELECT pg_sleep(1);
+ pg_sleep 
+----------
  
 (1 row)
 
@@ -81,6 +88,19 @@ SELECT query,calls FROM pg_stat_monitor ORDER BY query COLLATE "C";
  end $$                                                                                            | 
 (3 rows)
 
+ALTER SYSTEM SET pg_stat_monitor.track TO 'top';
+SELECT pg_reload_conf();
+ pg_reload_conf 
+----------------
+ t
+(1 row)
+
+SELECT pg_sleep(1);
+ pg_sleep 
+----------
+ 
+(1 row)
+
 SELECT pg_stat_monitor_reset();
  pg_stat_monitor_reset 
 -----------------------

regression/sql/counters.sql

@@ -12,9 +12,12 @@ SELECT a,b,c,d FROM t1, t2, t3, t4 WHERE t1.a = t2.b AND t3.c = t4.d ORDER BY a;
 SELECT a,b,c,d FROM t1, t2, t3, t4 WHERE t1.a = t2.b AND t3.c = t4.d ORDER BY a;
 SELECT a,b,c,d FROM t1, t2, t3, t4 WHERE t1.a = t2.b AND t3.c = t4.d ORDER BY a;
 SELECT query,calls FROM pg_stat_monitor ORDER BY query COLLATE "C";
+
+ALTER SYSTEM SET pg_stat_monitor.track TO 'all';
+SELECT pg_reload_conf();
+SELECT pg_sleep(1);
 SELECT pg_stat_monitor_reset();
 
-SELECT pg_stat_monitor_reset();
 do $$
 declare
    n integer:= 1;
@@ -26,6 +29,10 @@ begin
 	end loop;
 end $$;
 SELECT query,calls FROM pg_stat_monitor ORDER BY query COLLATE "C";
+
+ALTER SYSTEM SET pg_stat_monitor.track TO 'top';
+SELECT pg_reload_conf();
+SELECT pg_sleep(1);
 SELECT pg_stat_monitor_reset();
 
 DROP TABLE t1;