Tell LLVM that the negation in `<*const T>::sub` cannot overflow Today it's just `sub` <https://rust.godbolt.org/z/8EzEPnMr5>; with this PR it's `sub nsw`.
Tell LLVM that the negation in `<*const T>::sub` cannot overflow Today it's just `sub` <https://rust.godbolt.org/z/8EzEPnMr5>; with this PR it's `sub nsw`.