BUG=v8:8395,v8:8510

Change-Id: I1571877d709d6cc37966ace9014fa327e0820a80
Reviewed-on: https://chromium-review.googlesource.com/c/1417634
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58919}