Handling of sublinks within outer-level aggregates.

-- !query 39
select
 (select max((select i.unique2 from tenk1 i where i.unique1 = o.unique1)))
from tenk1 o
-- !query 39 schema
struct<>
-- !query 39 output
org.apache.spark.sql.AnalysisException
cannot resolve '`o.unique1`' given input columns: [i.two, i.odd, i.string4, i.ten, i.twothousand, i.thousand, i.fivethous, i.stringu2, i.hundred, i.unique1, i.stringu1, i.twenty, i.even, i.four, i.tenthous, i.unique2]; line 2 pos 63