Address special case condiction for U+017F.

Bug: v8:9356
Change-Id: Id24e5e2c999b198bf0f696aea8c98f223508c051
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1827683
Commit-Queue: Frank Tang <ftang@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64028}