The file contains testing features only used in d8. This CL prepares
deprecation and moves the logic into d8.cc.

Bug: v8:9941
Change-Id: I71de4cfd41d8f9fa209f936744cb170856365a6e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1899774Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Auto-Submit: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64800}