The validation was too strong in the case where the incrementation
produces type None.

Bug: chromium:1236716
Change-Id: I948b370594fa7dad1ba6e5b951f473855bf1346b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3097865Reviewed-by: Nico Hartmann <nicohartmann@chromium.org>
Commit-Queue: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#76338}