patch applied (ghc-6.10/ghc): TcSimplify.reduceImplication: clean up

[Ian Lynagh]

Wed Oct  1 02:13:15 PDT 2008  Manuel M T Chakravarty <chak at cse.unsw.edu.au>
  * TcSimplify.reduceImplication: clean up
  - This cleans up some of the mess in reduceImplication and documents the
    precondition on the form of wanted equalities properly.
  - I also made the back off test a bit smarter by allowing to back off in the
    presence of wanted equalities as long as none of them got solved in the
    attempt.  (That should save generating some superfluous bindings.)
  
    MERGE TO 6.10

    M ./compiler/typecheck/Inst.lhs -32 +16
    M ./compiler/typecheck/TcSimplify.lhs -57 +74
    M ./compiler/typecheck/TcTyFuns.lhs -2 +2

View patch online:
http://darcs.haskell.org/ghc-6.10/ghc/_darcs/patches/20081001091315-6295e-9b4feff6358e75abd4b4e0954bef0d4559366482.gz