ThreadSafetyAnalysis can not use assertion that a RunLoop is current
<rdar://problem/100313515>
Pull request: https://github.com/WebKit/WebKit/pull/4622
Committed 254856@main (7ff01e452a8c): <https://commits.webkit.org/254856@main> Reviewed commits have been landed. Closing PR #4622 and removing active labels.