tuple.* does not make names accessible in an unqualified form

[alexey-milovidov]

Use case

SELECT a, b FROM
(
  SELECT obj.* FROM
  (
    SELECT arrayJoin(x) AS obj FROM
    (
      SELECT [(1, 'Hello'), (2, 'World')]::Array(Tuple(a UInt8, b String)) AS x
    )
  )
)