StateBase requires a virtual destructor as it is destroyed through the
base class. Failing to provide a virtual dtor leaks internal state in
State (and possible in future RootState).

Bug: chromium:1056170
Change-Id: I4408a57dc05fdeb81408f571dd6eb87312ba7c9d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2964815Reviewed-by: Omer Katz <omerkatz@chromium.org>
Commit-Queue: Omer Katz <omerkatz@chromium.org>
Auto-Submit: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75160}