[GHC] #10194: Shouldn't this require ImpredicativeTypes?

[GHC]

#10194: Shouldn't this require ImpredicativeTypes?
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        Reporter:  kosmikus          |                   Owner:
            Type:  bug               |                  Status:  closed
        Priority:  normal            |               Milestone:  7.10.2
       Component:  Compiler (Type    |                 Version:  7.8.4
  checker)                           |                Keywords:
      Resolution:  fixed             |            Architecture:
Operating System:  Unknown/Multiple  |  Unknown/Multiple
 Type of failure:  GHC accepts       |               Test Case:
  invalid program                    |  typecheck/should_fail/T10194
      Blocked By:                    |                Blocking:
 Related Tickets:                    |  Differential Revisions:
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Comment (by refold):

 Apparently this fix means that some programs that compiled with 7.10.1 now
 fail with 7.10.2. One reported example is `xmonad-contrib`.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10194#comment:7>
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