pg_stat_statements: Add test coverage for pg_stat_statements_1_8()

This requires reading pg_stat_statements at least once while the 1.8
version of the extension is installed.

Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://www.postgresql.org/message-id/flat/40d1e4f2-835f-448f-a541-8ff5db75bf3d@eisentraut.org

contrib/pg_stat_statements/expected/oldextversions.out

@@ -88,6 +88,17 @@ SELECT count(*) > 0 AS has_data FROM pg_stat_statements;
 
 -- New functions and views for pg_stat_statements in 1.8
 AlTER EXTENSION pg_stat_statements UPDATE TO '1.8';
+SELECT pg_get_functiondef('pg_stat_statements_reset'::regproc);
+                                                       pg_get_functiondef                                                       
+--------------------------------------------------------------------------------------------------------------------------------
+ CREATE OR REPLACE FUNCTION public.pg_stat_statements_reset(userid oid DEFAULT 0, dbid oid DEFAULT 0, queryid bigint DEFAULT 0)+
+  RETURNS void                                                                                                                 +
+  LANGUAGE c                                                                                                                   +
+  PARALLEL SAFE STRICT                                                                                                         +
+ AS '$libdir/pg_stat_statements', $function$pg_stat_statements_reset_1_7$function$                                             +
+ 
+(1 row)
+
 \d pg_stat_statements
                     View "public.pg_stat_statements"
        Column        |       Type       | Collation | Nullable | Default 
@@ -125,15 +136,10 @@ AlTER EXTENSION pg_stat_statements UPDATE TO '1.8';
  wal_fpi             | bigint           |           |          | 
  wal_bytes           | numeric          |           |          | 
 
-SELECT pg_get_functiondef('pg_stat_statements_reset'::regproc);
+SELECT count(*) > 0 AS has_data FROM pg_stat_statements;
-                                                       pg_get_functiondef                                                       
+ has_data 
---------------------------------------------------------------------------------------------------------------------------------
+----------
- CREATE OR REPLACE FUNCTION public.pg_stat_statements_reset(userid oid DEFAULT 0, dbid oid DEFAULT 0, queryid bigint DEFAULT 0)+
+ t
-  RETURNS void                                                                                                                 +
-  LANGUAGE c                                                                                                                   +
-  PARALLEL SAFE STRICT                                                                                                         +
- AS '$libdir/pg_stat_statements', $function$pg_stat_statements_reset_1_7$function$                                             +
- 
 (1 row)
 
 -- New function pg_stat_statement_info, and new function

contrib/pg_stat_statements/sql/oldextversions.sql

@@ -33,8 +33,9 @@ SELECT count(*) > 0 AS has_data FROM pg_stat_statements;
 
 -- New functions and views for pg_stat_statements in 1.8
 AlTER EXTENSION pg_stat_statements UPDATE TO '1.8';
-\d pg_stat_statements
 SELECT pg_get_functiondef('pg_stat_statements_reset'::regproc);
+\d pg_stat_statements
+SELECT count(*) > 0 AS has_data FROM pg_stat_statements;
 
 -- New function pg_stat_statement_info, and new function
 -- and view for pg_stat_statements introduced in 1.9