patch applied (ghc): Bale out before renamer errors are duplicated

[Simon Peyton Jones]

Fri Oct  6 07:02:50 PDT 2006  simonpj at microsoft.com
  * Bale out before renamer errors are duplicated
  
  With the new Haddock patch, renamer errors can be duplicated;
  so we want to bale out before doing the Haddock stuff if errors
  are found.
  
  (E.g test mod67 shows this up.)
  

    M ./compiler/rename/RnSource.lhs +4