last_index_ is already incremented in Enqueue and points to one past
the end of the array.

Bug: v8:12054
Change-Id: I63b9a315464af9366f39c863fbd40e58adb69f1b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3233230
Commit-Queue: Victor Gomes <victorgomes@chromium.org>
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Auto-Submit: Victor Gomes <victorgomes@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/main@{#77469}