deps: back-port b049d1a from V8 upstream

Original commit message:

    Ensure we align zone memory at 8 byte boundaries on all platforms

    BUG=v8:5668
    R=verwaest@chromium.org

    Review-Url: https://codereview.chromium.org/2672203002
    Cr-Commit-Position: refs/heads/master@{#42959}

PR-URL: https://github.com/nodejs/node/pull/11204


Reviewed-By: Ali Ijaz Sheikh <ofrobots@google.com>
Reviewed-By: James M Snell <jasnell@gmail.com>