see https://crrev.com/c/1627548
that CL remove this functions declaration in the header file, but did not
drop function definition in the cpp file.

Bug: v8:9183
Change-Id: I98bba3664510c0a6a6a047a8b9c7c43bcc4c3962
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1631812
Auto-Submit: Yu Yin <xwafish@gmail.com>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61884}