patch applied (ghc-6.8/ghc): MERGED: Make the treatment of equalities more uniform

[Ian Lynagh]

Sun Jan 13 06:16:53 PST 2008  Ian Lynagh <igloo at earth.li>
  * MERGED: Make the treatment of equalities more uniform
  simonpj at microsoft.com**20080107142306
  
   This patch (which is part of the fix for Trac #2018) makes coercion variables
   be handled more uniformly.  Generally, they are treated like dictionaries
   in the type checker, not like type variables, but in a couple of places we
   were treating them like type variables.  Also when zonking we should use
   zonkDictBndr not zonkIdBndr.

    M ./compiler/hsSyn/HsBinds.lhs -2 +2
    M ./compiler/hsSyn/HsPat.lhs -3 +4
    M ./compiler/typecheck/TcHsSyn.lhs -2 +2
    M ./compiler/typecheck/TcMType.lhs +1
    M ./compiler/typecheck/TcSimplify.lhs -1 +1
    M ./compiler/typecheck/TcTyFuns.lhs -1 +1
    M ./compiler/typecheck/TcType.lhs -3 +1
    M ./compiler/typecheck/TcUnify.lhs -1 +1
    M ./compiler/types/FamInstEnv.lhs -1 +1
    M ./compiler/types/TypeRep.lhs -15 +22