Array detection (was Re: Final iterator spec)

[Peter van der Zee]

> Depends upon what you mean by "Array detection".  If you mean is obj an "exotic array object (ie, an object that automatically updates the length property value as integer indexed properties are added or deleted) then Array.isArray(obj) detects exactly that.

Okay cool. Is there merit in consistency for this? Iterators getting
an `isIterator()` method perhaps?

- peter