Only ref types can be nullable and since we have two different kinds for nullable and non-nullable refs we don't need to maintain the nullability flag.
Pull request: https://github.com/WebKit/WebKit/pull/4034
<rdar://problem/99819846>
Committed 254384@main (2f87b6ae16ad): <https://commits.webkit.org/254384@main> Reviewed commits have been landed. Closing PR #4034 and removing active labels.