behavior change of the pretty printer

[Kazu Yamamoto (=?iso-2022-jp?B?GyRCOzNLXE9CSScbKEI=?=)]

Hi,

Testing a package with GHC head on Travis CI, I got the following
error:

----
expected: Just (HTTPDate {hdYear = 1994, hdMonth = 11, hdDay = 15, hdHour = 8, hdMinute = 12, hdSecond = 31, hdWkday = 2})

 but got: Just HTTPDate {hdYear = 1994, hdMonth = 11, hdDay = 15, hdHour = 8, hdMinute = 12, hdSecond = 31, hdWkday = 2}
----

That is, parentheses are not printed. Is this an intentional change of
GHC head?

--Kazu