patch applied (ghc): Fix Trac #2701: make deriving check better for unlifted args

[Simon Peyton Jones]

Sat Oct 25 10:12:11 PDT 2008  simonpj at microsoft.com
  * Fix Trac #2701: make deriving check better for unlifted args
  
  Getting the automatic deriving mechanism to work really smoothly
  is surprisingly hard.  I keep finding myself in TcDeriv!
  
  Anyway, this is a nice clean fix to Trac #2701.
  

    M ./compiler/typecheck/TcDeriv.lhs -9 +27
    M ./compiler/typecheck/TcGenDeriv.lhs -6 +3

View patch online:
http://darcs.haskell.org/ghc/_darcs/patches/20081025171211-1287e-21d6fa17e0b2f4a8edeaef70a84371d65d902e0e.gz