patch applied (ghc-6.10/ghc): Proper error message for unsupported pattern signatures

[Ian Lynagh]

Wed Oct  1 07:43:39 PDT 2008  Manuel M T Chakravarty <chak at cse.unsw.edu.au>
  * Proper error message for unsupported pattern signatures
  - Pattern signatures must be identical to the type expected for the pattern;
    see Note [Pattern coercions]
  - We now signal an appropriate error if an equality coercion would be needed
    (instead of just generating Core that doesn't typecheck)
  
    MERGE TO 6.10

    M ./compiler/typecheck/TcHsType.lhs -5 +8
    M ./compiler/typecheck/TcPat.lhs -1 +8

View patch online:
http://darcs.haskell.org/ghc-6.10/ghc/_darcs/patches/20081001144339-6295e-e5330d4826cdbe8ab3a70fe476029fe8488f5fe5.gz