patch applied (ghc): FIX Trac #1825: standalone deriving Typeable

[Simon Peyton Jones]

Tue Nov 20 04:57:32 PST 2007  simonpj at microsoft.com
  * FIX Trac #1825: standalone deriving Typeable
  
  Standalone deriving of typeable now requires you to say
  	instance Typeable1 Maybe
  which is exactly the shape of instance decl that is generated
  by a 'deriving( Typeable )' clause on the data type decl.
  
  This is a bit horrid, but it's the only consistent way, at least
  for now.  If you say something else, the error messages are helpful.
  
  MERGE to 6.8 branch
  

    M ./compiler/typecheck/TcDeriv.lhs -59 +70
    M ./compiler/typecheck/TcRnMonad.lhs +13