[patch] Fix pr9701

[Rafael Espíndola]

On 3 September 2013 21:11, Richard Smith <richard at metafoo.co.uk> wrote:
> What about -munknown-to-clang-option? We really want an error on those ones,
> since they can change the ABI.

The behavior of -funknown-to-clang-option, -Wunknown-to-clang-option
and -munknown-to-clang-option is unchanged (we just warn). I think we
should be more strict about these too, but since they are the most
common options I would like to change them in a follow up patch.

Cheers,
Rafael