The test ensures that in-construction objects that have been found
through a write barrier are properly processed (marked + trace) when
finalizing the collection conservatively with a different stack.

This is a test for https://crrev.com/c/2744074

Bug: chromium:1056170
Change-Id: I8099bca1fb9025a315a8f0a3530aac822d1c45d2
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2745334Reviewed-by: Omer Katz <omerkatz@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73306}