Optimize IntersectionObserver::computeIntersectionState() for RenderInlines
<rdar://problem/113238475>
Pull request: https://github.com/WebKit/WebKit/pull/16299
Committed 266501@main (32beea64ac2d): <https://commits.webkit.org/266501@main> Reviewed commits have been landed. Closing PR #16299 and removing active labels.