[GHC] #10493: Inaccessible code might be accessible with newtypes and Coercible

[GHC]

#10493: Inaccessible code might be accessible with newtypes and Coercible
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        Reporter:  goldfire          |                Owner:  goldfire
            Type:  bug               |               Status:  closed
        Priority:  normal            |            Milestone:  7.10.3
       Component:  Compiler          |              Version:  7.10.1
      Resolution:  fixed             |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
                                     |  typecheck/should_compile/T10493
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by bgamari):

 I was able to cherry-pick 228ddb95ee137e7cef02dcfe2521233892dd61e0 to
 `ghc-7.10`. Unfortunately ff82387d6fe61762fe4f507e8f9799f5bdc3c43a appears
 to depend upon the superclass rework so I think I'll just have to punt on
 all of this.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10493#comment:10>
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