Make DocumentClass an OptionSet
Blocked on https://bugs.webkit.org/show_bug.cgi?id=233275 due to the CSS JIT
Created attachment 444552 [details] WIP
Oops. This was supposed to be just a WIP, not a patch for review.
Created attachment 444978 [details] Patch
Created attachment 444983 [details] Patch
Created attachment 445034 [details] EWS test
Created attachment 445044 [details] EWS test 2
Committed r286151 (244535@main): <https://commits.webkit.org/244535@main>
<rdar://problem/85731086>