Iterator-helper objects: .next value read returns undefined (bind-delegation impossible) #9068

Reading .next as a VALUE off an iterator-helper object returns undefined; Node 26.5.1 returns the function.

const h: any = [1, 2].values().map((x: number) => x * 2);
console.log(typeof h.next);   // node: "function"   perry: "undefined"
const orig = h.next.bind(h);  // node: ok           perry: TypeError: Bind must be called on a function

Calling h.next() works fine — the class-id method tower dispatches it — only the property read misses, because ITERATOR_HELPER_CLASS_ID objects have no attached prototype carrying next and no bound-method synthesis on the read path. Consequence: the orig = it.next.bind(it)-style delegation that #9019/#9066 made work on the array/map/set/string/buffer/regexp families is impossible on helpers (an own next patch on a helper is honored since #9066 — only the read of the builtin is missing).

Found while validating #9066 on this exact probe; the buffer and regexp-string families resolve the read fine, so this is helper-specific. Pre-existing relative to #9066 (that PR touches the write/dispatch paths only, not property reads).