[GHC] #9607: Type checking regression between GHC 7.6 and 7.8

[GHC]

#9607: Type checking regression between GHC 7.6 and 7.8
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              Reporter:  jstolarek   |            Owner:
                  Type:  bug         |           Status:  closed
              Priority:  normal      |        Milestone:
             Component:  Compiler    |          Version:  7.8.3
  (Type checker)                     |         Keywords:
            Resolution:  invalid     |     Architecture:  Unknown/Multiple
      Operating System:              |       Difficulty:  Unknown
  Unknown/Multiple                   |       Blocked By:
       Type of failure:  GHC         |  Related Tickets:
  rejects valid program              |
             Test Case:              |
              Blocking:              |
Differential Revisions:              |
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Comment (by simonpj):

 I'm going to re-open, because I'd like to collect examples of where
 ambiguity was actively sought in the wild.  However I don't propose any
 action right now.

 Simon

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9607#comment:4>
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