[GHC] #12408: "ghc: panic! (the 'impossible' happened)" only when compiled with "-O"

[GHC]

#12408: "ghc: panic! (the 'impossible' happened)" only when compiled with "-O"
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        Reporter:  clinton           |                Owner:
            Type:  bug               |               Status:  closed
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.0.1
      Resolution:  fixed             |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Compile-time      |  Unknown/Multiple
  crash                              |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Changes (by bgamari):

 * status:  merge => closed
 * resolution:   => fixed


Comment:

 Indeed the example compiles fine with
 b5ec09dff6b865550f3bd225f86028a304596c61.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12408#comment:2>
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