ARIA "name prohibited" list may be testable

[cookiecrook]

ARIA "name prohibited" list may be testable.
https://w3c.github.io/aria/#namefromprohibited

For example, <p aria-label="foo">test</p> should not return a label of test, and—if the implementation details agree—should have an empty label. "test" is a accessibility tree text node inside the para, not its label.

[cookiecrook]

This is not tracked in #3 but we may be able to get it in by the end of the year anyway.

[cookiecrook]

@jnurthen do you agree with my read of the current testability?

[cookiecrook]

We discussed and agreed that though this is an author error, it would violate the HTML Priorities of Constituencies to turn that into a requirement that the User Agent MUST NOT expose the value.... So closing this one as not testable.