[GHC] #7710: AutoDeriveTypeable and synonyms

[GHC]

#7710: AutoDeriveTypeable and synonyms
--------------------------------------+-------------------------------------
Reporter:  monoidal                   |          Owner:                  
    Type:  bug                        |         Status:  new             
Priority:  normal                     |      Component:  Compiler        
 Version:  7.7                        |       Keywords:                  
      Os:  Unknown/Multiple           |   Architecture:  Unknown/Multiple
 Failure:  GHC rejects valid program  |      Blockedby:                  
Blocking:                             |        Related:                  
--------------------------------------+-------------------------------------
 {{{
 {-# LANGUAGE AutoDeriveTypeable, DeriveDataTypeable, TypeSynonymInstances
 #-}
 type T = Int
 }}}

 reports duplicate instance for `Typeable Int` error. In my opinion type
 synonyms should be excluded from -XAutoDeriveTypeable.

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7710>
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