[GHC] #10775: Enable PolyKinds in GHC.Generics

[GHC]

#10775: Enable PolyKinds in GHC.Generics
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        Reporter:  RyanGlScott       |                   Owner:
            Type:  feature request   |                  Status:  new
        Priority:  normal            |               Milestone:
       Component:  libraries/base    |                 Version:  7.10.2
      Resolution:                    |                Keywords:
Operating System:  Unknown/Multiple  |            Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |               Test Case:
      Blocked By:                    |                Blocking:
 Related Tickets:                    |  Differential Revisions:
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Comment (by RyanGlScott):

 bgamari: The output of `-ddump-deriv` is extremely long, but here are the
 parts pertaining to `Proxy`:

 {{{
 ==================== Derived instances ====================
 Derived instances:
   instance forall (k_a21F :: BOX) (t_a21G :: k_a21F).
            GHC.Generics.Generic (Data.Proxy.Proxy t_a21G) where
     GHC.Generics.from Data.Proxy.Proxy
       = GHC.Generics.M1 (GHC.Generics.M1 GHC.Generics.U1)
     GHC.Generics.to (GHC.Generics.M1 (GHC.Generics.M1 GHC.Generics.U1))
       = Data.Proxy.Proxy

   instance GHC.Generics.Datatype where
     GHC.Generics.datatypeName _ = "Proxy"
     GHC.Generics.moduleName _ = "Data.Proxy"
     GHC.Generics.packageName _ = "base"

   instance GHC.Generics.Constructor where
     GHC.Generics.conName _ = "Proxy"

 Generic representation:

   Generated datatypes for meta-information:
     GHC.Generics.D1Proxy
     GHC.Generics.C1_0Proxy

   Representation types:
     type GHC.Generics.Rep (Data.Proxy.Proxy t_a21E) = GHC.Generics.D1
 }}}

 That definitely doesn't look right, especially since it should be that
 `Rep (Proxy t) = D1 D1Proxy (C1 C1_0Proxy U1)`.

 Luckily, this may be a moot issue. I wasn't aware of Phab:D493, which
 happens to enable `PolyKinds` in `GHC.Generics` as a happy coincidence.
 Therefore, this is probably a duplicate of #9766.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10775#comment:5>
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