[GHC] #12719: master branch broken with alex 3.2

[GHC]

#12719: master branch broken with alex 3.2
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           Reporter:  bgamari        |             Owner:  bgamari
               Type:  task           |            Status:  new
           Priority:  highest        |         Milestone:  8.2.1
          Component:  Compiler       |           Version:  8.0.1
           Keywords:                 |  Operating System:  Unknown/Multiple
       Architecture:                 |   Type of failure:  None/Unknown
  Unknown/Multiple                   |
          Test Case:                 |        Blocked By:
           Blocking:                 |   Related Tickets:
Differential Rev(s):                 |         Wiki Page:
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 The build fails with all sorts of type errors. Need to work out what is
 going on when there is time.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12719>
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