patch applied (ghc-6.10/ghc): MERGED: Improve error reporting for 'deriving'

[Ian Lynagh]

Sun Jan  4 05:15:43 PST 2009  Ian Lynagh <igloo at earth.li>
  * MERGED: Improve error reporting for 'deriving'
  simonpj at microsoft.com**20081231143521
   
   a) Improve the extra suggested fix when there's a "no instance"
      error in a deriving clause.
   
   b) Improve error location recording in tcInstDecl2
   
   Many of the changes in tcInstDecl2 are simple reformatting.

    M ./compiler/typecheck/TcDeriv.lhs -3 +1
    M ./compiler/typecheck/TcInstDcls.lhs -30 +33
    M ./compiler/typecheck/TcSimplify.lhs -11 +15

View patch online:
http://darcs.haskell.org/ghc-6.10/ghc/_darcs/patches/20090104131543-3fd76-9eeb5eaa3afe0a1fa73899e5e92b74d87700a716.gz