patch applied (ghc): Make SpecConstr work again

[Simon Peyton Jones]

Thu Nov 15 00:42:42 PST 2007  simonpj at microsoft.com
  * Make SpecConstr work again
  
  In a typo I'd written env instead of env', and as a result RULES are
  practically guaranteed not to work in a recursive group.  This pretty
  much kills SpecConstr in its tracks!
  
  Well done Kenny Lu for spotting this.  The fix is easy.
  
  Merge into 6.8 please.
  
  
  

    M ./compiler/simplCore/Simplify.lhs -1 +1