[GHC] #9071: Panic with -XDeriveFunctor when deriving from a non-Functor in a separate module

[GHC]

#9071: Panic with -XDeriveFunctor when deriving from a non-Functor in a separate
module
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        Reporter:  bens                |            Owner:
            Type:  bug                 |           Status:  new
        Priority:  normal              |        Milestone:
       Component:  Compiler            |          Version:  7.8.2
      Resolution:                      |         Keywords:
Operating System:  Unknown/Multiple    |     Architecture:
 Type of failure:  Compile-time crash  |  Unknown/Multiple
       Test Case:                      |       Difficulty:  Unknown
        Blocking:                      |       Blocked By:
                                       |  Related Tickets:
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Comment (by bens):

 It also crashes when running ghc directly, as in

 `ghc --make -isrc src/Main.hs`

 with any level of optimisation.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9071#comment:1>
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