childNodes returned a plain Array (constructor "Array"), and NodeList
extended Array, so Array.isArray(list) was true and
Object.prototype.toString reported "[object Array]". A real browser
reports "[object NodeList]" and Array.isArray is false, which
feature-detection and fingerprinting scripts check.
NodeList is now its own type with the array-like surface scripts use
(indexed access, length, item, forEach, entries/keys/values, iteration),
and childNodes goes through it. Verified spread, for..of, and Array.from
still work.
Refs #335.
SGavrl
25ce541ec8