[Bug driver/115990] Consider deprecating -Ofast

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115990

--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Aaron Ballman from comment #3).
> > 
> > People will never read the documentation either way anyways.
> 
> Agreed, that's part of why we're deprecating.

That is a real bad excuse really.

Also -Ofast for gcc is more than just -O3 -ffast-math. It enables unrolling
loops and more.