Bug fix: Error from VALUES as subquery in JOIN

Fix for this query:

`SELECT *  FROM (VALUES (1,'a'),(2,'b')) AS t1(id,s) INNER JOIN (VALUES (2,'y'),(3,'z')) AS t2(id,s2) USING (id)`

```
ERROR:  Unknown join element: ExpressionsSource@1c2826fd([[1, a], [2, b]])