Always make a BufferAccessStrategy for ANALYZE

32fbe0239 changed things so we didn't bother allocating the
BufferAccessStrategy during VACUUM (ONLY_DATABASE_STATS); and VACUUM
(FULL), however, it forgot to consider that VACUUM (FULL, ANALYZE) is a
possible combination.  That change would have resulted in such a command
allowing ANALYZE to make full use of shared buffers, which wasn't
intended, so fix that.

Reported-by: Melanie Plageman
Discussion: https://postgr.es/m/CAAKRu_bJRKe+v_=OqwC+5sA3j5qv8rqdAwy3+yHaO3wmtfrCRg@mail.gmail.com

src/backend/commands/vacuum.c

@@ -393,11 +393,13 @@ vacuum(List *relations, VacuumParams *params,
 	 * If caller didn't give us a buffer strategy object, make one in the
 	 * cross-transaction memory context.  We needn't bother making this for
 	 * VACUUM (FULL) or VACUUM (ONLY_DATABASE_STATS) as they'll not make use
-	 * of it.
+	 * of it.  VACUUM (FULL, ANALYZE) is possible, so we'd better ensure that
+	 * we make a strategy when we see ANALYZE.
 	 */
 	if (bstrategy == NULL &&
-		(params->options & (VACOPT_ONLY_DATABASE_STATS |
-							VACOPT_FULL)) == 0)
+		((params->options & (VACOPT_ONLY_DATABASE_STATS |
+							 VACOPT_FULL)) == 0 ||
+		 (params->options & VACOPT_ANALYZE) != 0))
 	{
 		MemoryContext old_context = MemoryContextSwitchTo(vac_context);