patch applied (cabal): Get the correct value of $topdir on Windows with GHC 6.12.1

[Ian Lynagh]

Wed Dec 30 12:46:13 PST 2009  Ian Lynagh <igloo at earth.li>
  * Get the correct value of $topdir on Windows with GHC 6.12.1

    M ./Distribution/Simple/GHC.hs -4 +15
    M ./Distribution/Simple/Haddock.hs -8 +3

View patch online:
http://darcs.haskell.org/cabal/_darcs/patches/20091230204613-3fd76-7e6e71f0e6485fdb57041f7f3c2ac290e238d71f.gz