Add ORDER BY to regression test case

Apparently, the output order is different on different endianness, per
build farm member snapper.

src/test/regress/expected/collate.icu.utf8.out

@@ -1372,18 +1372,18 @@ SELECT x FROM test2ci UNION SELECT x FROM test1ci ORDER BY x;
  ghi
 (3 rows)
 
-SELECT x FROM test1ci INTERSECT SELECT x FROM test2ci;
+SELECT x FROM test1ci INTERSECT SELECT x FROM test2ci ORDER BY x;
   x  
 -----
- ghi
  abc
+ ghi
 (2 rows)
 
-SELECT x FROM test2ci INTERSECT SELECT x FROM test1ci;
+SELECT x FROM test2ci INTERSECT SELECT x FROM test1ci ORDER BY x;
   x  
 -----
- ghi
  ABC
+ ghi
 (2 rows)
 
 SELECT x FROM test1ci EXCEPT SELECT x FROM test2ci;

src/test/regress/sql/collate.icu.utf8.sql

@@ -517,8 +517,8 @@ SELECT x FROM test3ci WHERE x SIMILAR TO 'a%';
 SELECT x FROM test3ci WHERE x ~ 'a';
 SELECT x FROM test1ci UNION SELECT x FROM test2ci ORDER BY x;
 SELECT x FROM test2ci UNION SELECT x FROM test1ci ORDER BY x;
-SELECT x FROM test1ci INTERSECT SELECT x FROM test2ci;
-SELECT x FROM test2ci INTERSECT SELECT x FROM test1ci;
+SELECT x FROM test1ci INTERSECT SELECT x FROM test2ci ORDER BY x;
+SELECT x FROM test2ci INTERSECT SELECT x FROM test1ci ORDER BY x;
 SELECT x FROM test1ci EXCEPT SELECT x FROM test2ci;
 SELECT x FROM test2ci EXCEPT SELECT x FROM test1ci;
 SELECT DISTINCT x FROM test3ci ORDER BY x;