BUG=v8:6243

Change-Id: Idb9aa8221248cc493c8f5ba4bd50fa712a57f5f8
Reviewed-on: https://chromium-review.googlesource.com/541221
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46249}