[patch] Don't accept -fno-{fixed,free}-form

[Tobias Schlüter]

Steven Bosscher wrote:
> It seems to me that we should disallow -fno-fixed-form and -fno-free-form.
> What do you think of that idea and of the following patch?
> 
> Gr.
> Steven
> 
> 	* lang.opt (ffixed-form, ffree-form): Reject negatives of
> 	these options.

It makes a lot of sense to me.

- Tobi