This CL adds a regression test that will check that the elements
pointer is properly reloaded after the JavaScript comparison
function is called during Array.p.sort.

R=jgruber@chromium.org

Bug: chromium:859809
Change-Id: I15f55fcc1906bd8d0751596e5457367a643b92da
Reviewed-on: https://chromium-review.googlesource.com/1124475
Commit-Queue: Simon Zünd <szuend@google.com>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54174}