Changes to ghc

Changes to ghc:
commit dd3a6d270f827a59f7a33f32facc506cb35af1fa
Author: Dr. ERDI Gergo <gergo@erdi.hu>
Date:   Sat Apr 12 16:35:44 2014 +0800

    Add source file for new test that checks that as-patterns are rejected
    in pattern synonym definitions