It was shipped in Chrome 62.

Bug: v8:5546, v8:4829
Cq-Include-Trybots: master.tryserver.v8:v8_linux_noi18n_rel_ng
Change-Id: I3ac318639f1f7483d4d4f4fe5606387a856be98a
Reviewed-on: https://chromium-review.googlesource.com/777940Reviewed-by: Georg Neis <neis@chromium.org>
Commit-Queue: Adam Klein <adamk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49687}

BUG=v8:6100

Change-Id: Ib8729b2688bbaf6fb397737ccf1b1c086698ab93
Reviewed-on: https://chromium-review.googlesource.com/455876
Commit-Queue: Wiktor Garbacz <wiktorg@google.com>
Reviewed-by: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#43822}