patch applied (ghc): Modify compileToCore to take just a filename

[Kirsten Chevalier]

Wed Jun 27 15:48:09 PDT 2007  Tim Chevalier <chevalier at alum.wellesley.edu>
  * Modify compileToCore to take just a filename
  
  Modified compileToCore to take just a session and a 
  filename, rather than a module name as well, since the module
  name can be computed from the filename. 

    M ./compiler/main/GHC.hs -5 +11