At the May 2018 TC39 meeting, they decided to rename Atomics.wake to
Atomics.notify. This change adds Atomics.notify as an alias, but does
not remove Atomics.wake, which will be removed later.

This allows for embedders to use either name to prevent
breaking tests. When the tests are switched over, we can remove
Atomics.wake.

Bug: v8:7883
Change-Id: If057ebff162bde975c6e1b60d83a4662f144e81f
Reviewed-on: https://chromium-review.googlesource.com/1142290
Commit-Queue: Ben Smith <binji@chromium.org>
Reviewed-by: Adam Klein <adamk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54534}