Fri Nov 10 05:31:23 PST 2006  simonpj <at> microsoft.com
  * Use implication constraints to improve type inference

    M ./compiler/typecheck/FamInst.lhs -1 +1
    M ./compiler/typecheck/Inst.lhs -48 +123
    M ./compiler/typecheck/TcArrows.lhs -4 +3
    M ./compiler/typecheck/TcBinds.lhs -6 +8
    M ./compiler/typecheck/TcClassDcl.lhs -6 +6
    M ./compiler/typecheck/TcEnv.lhs +3
    M ./compiler/typecheck/TcGadt.lhs -2 +17
    M ./compiler/typecheck/TcHsType.lhs -1
    M ./compiler/typecheck/TcInstDcls.lhs -6 +6
    M ./compiler/typecheck/TcMType.lhs -15 +33
    M ./compiler/typecheck/TcPat.lhs -7 +6
    M ./compiler/typecheck/TcRnDriver.lhs -42 +26
    M ./compiler/typecheck/TcRnTypes.lhs -29 +55
    M ./compiler/typecheck/TcRules.lhs -2 +3
    M ./compiler/typecheck/TcSimplify.lhs -716 +912
    M ./compiler/typecheck/TcSplice.lhs +1
    M ./compiler/typecheck/TcType.lhs -35 +27
    M ./compiler/typecheck/TcUnify.lhs -5 +6
    M ./compiler/types/FunDeps.lhs -1 +58