I forgot that WebKitPolicyDecision must be derivable. Although we're not very likely to ever use it, this vtable should still have more padding, just in case.
In addition to _WebKitPolicyDecisionClass, there is also JSCClassVTable. Another one that is probably not likely to grow beyond its current padding, but we should be cautious nonetheless.
Pull request: https://github.com/WebKit/WebKit/pull/10163
Committed 260396@main (7ca0c691aba6): <https://commits.webkit.org/260396@main> Reviewed commits have been landed. Closing PR #10163 and removing active labels.