patch applied (ghc): Remove unnecessary free-variables from renamer

[Simon Peyton Jones]

Wed Jun  6 06:25:21 PDT 2007  simonpj at microsoft.com
  * Remove unnecessary free-variables from renamer
  
  The renamer used to be responsible for making sure that all interfaces
  with instance decls (other than orphans) were loaded.  But TH makes that
  impossible, so the typechecker does it, via checkWiredInTyCon.
  
  This patch simply removes redundant additions to the free-variable set
  in the renamer, which were there, I believe, solely to ensure that the 
  instances came in.  Removing them should change nothing, but it's a 
  useful clean up.
  

    M ./compiler/iface/LoadIface.lhs +22
    M ./compiler/iface/TcIface.lhs -1 +4
    M ./compiler/rename/RnExpr.lhs -6 +3
    M ./compiler/rename/RnTypes.lhs -10 +6