[GHC] #13798: Invalid transformation in simplOptExpr

[GHC]

#13798: Invalid transformation in simplOptExpr
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        Reporter:  simonpj           |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.0.1
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by goldfire):

 A related question, while your attention is on this code, is why the case-
 of-known-constructor optimization immediately above this code doesn't
 detect the `Coercible_sc` selector applied to `MkCoercible`.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13798#comment:1>
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