... for length = 0, analogously to what e.g. NewFixedArray does.

Simplify some call sites that had special handling for this case
(there are others that didn't).

Change-Id: Ib3de5506300e967aca072fad53df7ab04ef68839
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3009225Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75629}