CanUseSameAccessor<ElementsAccessor: type> is array-sort.tq is super
performance-critical. Reverting the type-safe cleanup made in this
function while landing Array.prototype.slice.

Bug=chromium:852764

Change-Id: I1252d2ff8e431581f916794807e59abb39248abb
Reviewed-on: https://chromium-review.googlesource.com/c/1317815Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Daniel Clifford <danno@chromium.org>
Cr-Commit-Position: refs/heads/master@{#57248}