Do less HTMLCollection/NodeList invalidation when non-Element children are changed.
Pull request: https://github.com/WebKit/WebKit/pull/3628
Committed 253794@main (424de6f2e3e3): <https://commits.webkit.org/253794@main> Reviewed commits have been landed. Closing PR #3628 and removing active labels.
<rdar://problem/99156276>