[GHC] #12389: Limit duplicate export warnings for datatypes

[GHC]

#12389: Limit duplicate export warnings for datatypes
-------------------------------------+-------------------------------------
        Reporter:  dfeuer            |                Owner:  parsonsmatt
            Type:  feature request   |               Status:  new
        Priority:  normal            |            Milestone:  8.4.1
       Component:  Compiler          |              Version:  7.10.3
      Resolution:                    |             Keywords:  newcomer
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Incorrect         |  Unknown/Multiple
  warning at compile-time            |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #11959            |  Differential Rev(s):  Phab:D4134
       Wiki Page:                    |
-------------------------------------+-------------------------------------
Changes (by parsonsmatt):

 * owner:  (none) => parsonsmatt
 * differential:   => Phab:D4134


-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12389#comment:13>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler