message: added another test requested by mark
diff: @@ -23,3 +23,7 @@ SELECT (SELECT avg(0)) c0, (SELECT 0 OFFSET c0 + 1);
  ----
  Serialization Error: Cannot copy BoundSubqueryExpression
  +query II
  +select avg(0) AS c0, (SELECT c0);
  +----
  +0.0 0.0
  