Remove unused/unimplementation private method that has a NOLINT comment

Bug: v8:9429
Change-Id: I8c5de440c8b456586b3a7c1a92af2d9a1fca4e78
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1792231
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63690}