[GHC] #13549: GHC 8.2.1's typechecker rejects code generated by singletons that 8.0 accepts

[GHC]

#13549: GHC 8.2.1's typechecker rejects code generated by singletons that 8.0
accepts
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        Reporter:  RyanGlScott       |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  high              |            Milestone:  8.2.1
       Component:  Compiler (Type    |              Version:  8.0.1
  checker)                           |
      Resolution:                    |             Keywords:
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 RyanGlScott):

 Commit 109a2429493c2a2d5481b67f5b0c1086a959813e caused this regression.

 Richard, might you have an idea of what's going on here?

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13549#comment:2>
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