Minor documentation soundness hole in `Validity`?

[jswrenn]

Validity requires:

Any V: Validity must guarantee that this set is only a function of the bit validity of the referent type, T, and not of any other property of T.

...but Valid's guarantees concern both bit validity and safety. By this documentation, a Ptr::from_ref(&&42) is unsound, since the validity of the referent &42 depends its provenance, which isn't a property of bit validity.