Both of them shipped in Chrome 49 without incident.

Also move relevant tests from harmony/ to es6/.

Review URL: https://codereview.chromium.org/1815773002

Cr-Commit-Position: refs/heads/master@{#34964}

An array is either a JSArray or a proxy whose target is an array.

R=bmeurer@chromium.org
BUG=

Review URL: https://codereview.chromium.org/1497483004

Cr-Commit-Position: refs/heads/master@{#32558}