patch applied (ghc): Fix Trac #2179: error message for main

[Simon Peyton Jones]

Thu Apr  3 10:37:46 PDT 2008  simonpj at microsoft.com
  * Fix Trac #2179: error message for main
  
  A short-cut to generate the (runMainIO main) wrapper turned out
  to make a bad error message.  This should fix it.
  

    M ./compiler/typecheck/TcRnDriver.lhs -9 +16