Recently the test harness of the js-api spec tests got updated
to the test harness of wpt. With this CL we import the wpt test
harness into V8.

Some adjustments to the test harness had to be made. These additions
are in the new files report.js and testharness-additions.js

Bug: v8:10556
Change-Id: Ia5f7dec3f40ba8fc639135fb2b2078b9220eccf7
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2235116
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Reviewed-by: Emanuel Ziegler <ecmziegler@chromium.org>
Reviewed-by: Adam Klein <adamk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68355}