There are some types, like WebEventFlags, that must remain a plain-old enumeration as opposed to being turned into an OptionSet. We should support pretty printing such types.
Created attachment 358050 [details] Patch
Note that the proposed patch (attachment #358050 [details]) includes the patch for bug #193023. I am hoping that people do not disagree with the fix for bug #193023. If they do, then I will fix up this patch as applicable.
Comment on attachment 358050 [details] Patch 👍🏻
Created attachment 358341 [details] To Land
Committed r239651: <https://trac.webkit.org/changeset/239651>
<rdar://problem/47064007>