This ASSERT is not useful, since after https://bugs.webkit.org/show_bug.cgi?id=235189 we do a single traversal to compute all flags in the rare cases they aren't already initialized.
<rdar://problem/88134004>
Created attachment 450140 [details] Patch
Committed r288693 (246491@main): <https://commits.webkit.org/246491@main> All reviewed patches have been landed. Closing bug and clearing flags on attachment 450140 [details].