[GHC] #14991: GHC HEAD regression involving TYPEs in type families

[GHC]

#14991: GHC HEAD regression involving TYPEs in type families
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        Reporter:  RyanGlScott       |                Owner:  goldfire
            Type:  bug               |               Status:  new
        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:  GHC rejects       |  Unknown/Multiple
  valid program                      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by goldfire):

 I figured this one out. It turns out that `solveEqualities` needs to use
 `simpl_top`. In my recent patch, I thought I could get away with
 `solveWanteds`, and no test cases told me I couldn't. Easy enough to fix.
 Validating now.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14991#comment:5>
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