With the recent introduction of unicode sets (v-flag), nested character
classes are allowed in regular expressions.
We always expect a nested class to be of type
`RegExpClassSetExpression`, but the empty nested class was not handled
correctly.
Bug: v8:11935, chromium:1412942
Change-Id: I3b644c8627d8fc6b320a419216372810e8003983
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/4224311
Reviewed-by: Jakob Linke <jgruber@chromium.org>
Commit-Queue: Patrick Thier <pthier@chromium.org>
Cr-Commit-Position: refs/heads/main@{#85680}