[GHC] #13142: GHC emits enormous core starting with 'Arity decrease'

[GHC]

#13142: GHC emits enormous core starting with 'Arity decrease'
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        Reporter:  jeiea         |                Owner:
            Type:  bug           |               Status:  new
        Priority:  normal        |            Milestone:
       Component:  Compiler      |              Version:  8.0.2
      Resolution:                |             Keywords:
Operating System:  Windows       |         Architecture:  Unknown/Multiple
 Type of failure:  None/Unknown  |            Test Case:
      Blocked By:                |             Blocking:
 Related Tickets:                |  Differential Rev(s):
       Wiki Page:                |
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Changes (by jeiea):

 * Attachment "error.7z" added.

 stack verbose output

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13142>
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