What does the spec require when you call Object.defineProperty to change the `value` of a non-configurable, non-writable data property to a value that is the SAME (per SameValue) as the current one?
const o = {};
Object.defineProperty(o, 'k', { value: NaN, writable: false, configurable: false });
Object.defineProperty(o, 'k', { value: NaN });