One can get access to the constructor for the Array Iterator but the semantics of [[Call]] is not defined.
Array Iterator is neither a Constructor nor Callable, so I don't think [[Call]] (or [[Construct]]) needs to be defined at all. There is an empty "ArrayIterator.prototype.constructor" (15.4.5.2.1) entry, which needs to be removed, but that's it. Unless the current draft is incomplete and Array Iterator is supposed to be callable/constructable, of course.
The current implementation for Array Iterator in V8 provides access to a constructor, but that is a different issue.
There is a margin note in the doc file that says we need to decide whether we to expose this 'constructor' property and hence whether we want to make ArrayIterator visible.
I may be useful for user who want to create array-like abstrations. In the spec. we reuse it for typed array iteration.
we ended up not exposing an ArrayIterator constructor (same for other built-in iterators)