The new method is not implemented in Chrome or Node, and the issue has
no activity since 2018, so let's rip out the incomplete new API.

Drive-by: Sprinke a few V8_LIKELY and V8_UNLIKELY.

R=mlippautz@chromium.org

Bug: chromium:634547
Change-Id: I0dabad520d459277d7196fa69c1bbceaf4d53596
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3780528Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/main@{#81923}