This patch moves from using a hand-rolled serializer for CFCharacterSetRef to
<rdar://problem/122441215>
Pull request: https://github.com/WebKit/WebKit/pull/23975
Committed 274332@main (bec01ed582b0): <https://commits.webkit.org/274332@main> Reviewed commits have been landed. Closing PR #23975 and removing active labels.