[clang] [Driver][BoundsSafety] Add -fexperimental-bounds-safety flag (PR #70480)

[Yeoul Na via cfe-commits]

rapidsna wrote:

> > @MaskRay To be clear, the check is now in Driver as you suggested. It's just that the frontend also has some extra checks too. So, you want me to remove the extra checks in the frontend?
> 
> Yes, otherwise it's duplicated check.

I just removed the check in the frontend!



https://github.com/llvm/llvm-project/pull/70480