[commit: ghc] master's head updated: Merge branch 'master' of http://darcs.haskell.org/ghc (aaff876)

[Simon Peyton Jones]

Repository : ssh://darcs.haskell.org//srv/darcs/ghc

Branch 'master' now includes:

     bf6f708... Empty data types should not be "trimmed" by TidyPgm
     6b0537a... Respect kind-variable scoping when instantiating dfuns
     05debbb... Tiny refactoring; no change in behaviour
     aaff876... Merge branch 'master' of http://darcs.haskell.org/ghc