patch applied (packages/Cabal): Read the buildinfo for the haddock step.

[Duncan Coutts]

Thu Oct  5 14:21:38 PDT 2006  Duncan Coutts <duncan.coutts at worc.ox.ac.uk>
  * Read the buildinfo for the haddock step.
  In particular this means we pick up any cc-options that are
  needed for preprocessing the source before haddock reads it.
  This fixes the haddock build step for many of the packages in
  the ghc-extralibs collection.

    M ./Distribution/Simple.hs +1