[PATCH] MC: do not try to parse invalid handled directives

[Saleem Abdulrasool]

  Matheus, I do believe that you are correct.  The problem is that many directive handlers do:

      return Error(Loc, "message");

  This is problematic since this is quite idomatic in LLVM.  However, Error returns *true*.  The handlers simply encountered an error and are actually interested in the directive.  I will update the patch (and message) with a more "correct" fix, but, I dont see a good way to prevent this type of code in the future.

http://llvm-reviews.chandlerc.com/D2410