patch applied (ghc-fc2): fix bugs, add boolean flag to identify coercion variables

[chak at cse.unsw.edu.au]

Sun Aug  6 14:04:02 PDT 2006  Manuel M T Chakravarty <chak at cse.unsw.edu.au>
  * fix bugs, add boolean flag to identify coercion variables
  Tue Jul 25 06:20:05 EDT 2006  kevind at bu.edu

    M ./compiler/basicTypes/Var.lhs -8 +17
    M ./compiler/coreSyn/MkExternalCore.lhs +1
    M ./compiler/deSugar/Match.lhs -1 +4
    M ./compiler/deSugar/MatchLit.lhs -1 +1
    M ./compiler/hsSyn/HsExpr.lhs -1 +3
    M ./compiler/iface/BuildTyCl.lhs -2 +11
    M ./compiler/typecheck/TcType.lhs -6 +17
    M ./compiler/types/Type.lhs -2 +2
    M ./compiler/types/TypeRep.lhs -3 +5
    M ./utils/runstdtest/runstdtest.prl -3 +3