[GHC] #15380: Infinite typechecker loop in GHC 8.6

[GHC]

#15380: Infinite typechecker loop in GHC 8.6
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        Reporter:  RyanGlScott       |                Owner:  (none)
            Type:  bug               |               Status:  patch
        Priority:  high              |            Milestone:  8.6.1
       Component:  Compiler (Type    |              Version:  8.5
  checker)                           |             Keywords:  TypeInType,
      Resolution:                    |  TypeFamilies
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Compile-time      |  Unknown/Multiple
  performance bug                    |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D4974
       Wiki Page:                    |
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Comment (by simonpj):

 Richard and I discussed yesterday; he has a bit more to do and then will
 commmit.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15380#comment:4>
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