Since `Object.is` just directly returns `SameValue`, should this method `return Object.is(a, b) || (a === 0 && b === 0);`?

Alternatively, the body of `Object.is` could move to `ES.SameValue` and this could `return ES.SameValue(a, b) || (a === 0 && b === 0);` - that seems like it might match the spec language more clearly.