patch applied (ghc): Remove unused OccInfo (simplification)

[Simon Peyton Jones]

Thu Oct  5 06:03:27 PDT 2006  simonpj at microsoft.com
  * Remove unused OccInfo (simplification)
  
  The substitution used to carry "fragile" OccInfo to call sites via the
  DoneId constructor of SimplEnv.SimplSR.  This was always a tricky thing 
  to do, and for some time I've been removing the need for it.
  
  Now at last I think we can nuke it altogether.  Hooray.
  
  I did a full nonfib run, and got zero perf changes.
  

    M ./compiler/coreSyn/CoreUnfold.lhs -9 +3
    M ./compiler/simplCore/SimplEnv.lhs -27 +12
    M ./compiler/simplCore/SimplUtils.lhs -3 +3
    M ./compiler/simplCore/Simplify.lhs -4 +4