[GHC] #13407: Fix printing of higher-rank kinds

[GHC]

#13407: Fix printing of higher-rank kinds
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        Reporter:  goldfire          |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.0.1
      Resolution:                    |             Keywords:  TypeInType
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by RyanGlScott):

 Another higher-rank kind pretty-printing oddity:

 {{{#!hs
 {-# LANGUAGE RankNTypes #-}
 {-# LANGUAGE TypeFamilies #-}
 {-# LANGUAGE TypeInType #-}
 module Bug where

 import Data.Kind

 type family Foo (a :: Type) :: Type
 type instance Foo (a :: forall k. k -> Type) = Int
 }}}
 {{{
 GHCi, version 8.2.0.20170523: http://www.haskell.org/ghc/  :? for help
 Loaded GHCi configuration from /home/rgscott/.ghci
 [1 of 1] Compiling Bug              ( Bug.hs, interpreted )

 Bug.hs:9:19: error:
     • Expecting one more argument to ‘a k1’
       Expected a type, but ‘a k1’ has kind ‘k1 -> *’
     • In the first argument of ‘Foo’, namely
         ‘(a :: forall k. k -> Type)’
       In the type instance declaration for ‘Foo’
   |
 9 | type instance Foo (a :: forall k. k -> Type) = Int
   |                   ^^^^^^^^^^^^^^^^^^^^^^^^^^
 }}}

 The error message mentions `a k1`... how did that `k1` sneak in there?

 I'm not sure if it's due to the same root cause as the original issue, but
 thought it was worth mentioning.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13407#comment:2>
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