Oversight in commit b81ffa13e3.

Should warn if a materialized view may be affected, as well.

src/bin/pg_upgrade/check.c

@@ -1911,6 +1911,10 @@ check_for_unicode_update(ClusterInfo *cluster)
 		"  UNION "
 		"    SELECT partrelid "
 		"    FROM pg_partitioned_table, patterns WHERE partexprs::text ~ p "
+		"  UNION "
+		"    SELECT ev_class "
+		"    FROM pg_rewrite, pg_class, patterns "
+		"    WHERE ev_class = pg_class.oid AND relkind = 'm' AND ev_action::text ~ p"
 		"  ) s(reloid), pg_class c, pg_namespace n, pg_database d "
 		"  WHERE s.reloid = c.oid AND c.relnamespace = n.oid AND "
 		"        d.datname = current_database() AND "