Looks like historical leftovers from the time when we had "pixel arrays"
and external array elements kinds. See
https://codereview.chromium.org/1262583002

Bug: v8:11111
Change-Id: I288d47ae802218737bd6226cbb999c3289d1dbaf
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3574548Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Commit-Queue: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/main@{#79823}