This will enable people to check if an object is
document.all without having to use tricks like
`typeof v === 'undefined' && v !== undefined`.

Change-Id: I74670e4d3886fcd90f0f3cef9c3644a24ee08fda
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2067681Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#66412}