47797ad7e8
pushdown not slotreferences expr of on clause.
select * from t1 join t2 on t1.a + 1 = t2.b + 2 and t1.a + 1 > 2
project()
+---join(t1.a + 1 = t2.b + 2 && t1.a + 1 > 2)
|---scan(t1)
+---scan(t2)
transform to
project()
+---join(c = d && c > 2)
|---project(t1.a -> t1.a + 1)
| +---scan(t1)
+---project(t2.b -> t2.b + 2)
+---scan(t2)