patch applied (ghc-6.8/ghc): Fix Trac #1746: make rule-matching work properly with Cast expressions

[Ian Lynagh]

Sat Sep 29 03:44:06 PDT 2007  simonpj at microsoft.com
  * Fix Trac #1746: make rule-matching work properly with Cast expressions
  
  The Cast case of the rule-matcher was simply wrong.
  
  This patch fixes it; see Trac #1746.
  
  I also fixed the rule generation in SpecConstr to generate a wild-card
  for the cast expression, which we don't want to match on.  This makes
  the rule more widely applicable; it wasn't the cause of the bug.
  

    M ./compiler/specialise/Rules.lhs -5 +4
    M ./compiler/specialise/SpecConstr.lhs -7 +12
    M ./compiler/types/Unify.lhs -5 +32