I removed the padding field because I couldn't see a reason why we would
want to pad to system pointer size. I'm guessing that the intent was to
pad to tagged pointer size, which was once relevant but isn't anymore
since one of the int32 fields got removed.

Bug: v8:8952
Change-Id: Ic191d783efd8d686f6920e6e7ce2d3dacba883c5
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1776847Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#63556}