This is behind a new flag --harmony-namespace-exports.

Bug: v8:8101
Cq-Include-Trybots: luci.v8.try:v8_linux_noi18n_rel_ng
Change-Id: I9c252b6de2b08223fcf3296340b78d721471bdb4
Reviewed-on: https://chromium-review.googlesource.com/c/1258004
Commit-Queue: Georg Neis <neis@chromium.org>
Reviewed-by: Adam Klein <adamk@chromium.org>
Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56550}