Spec Text: https://tc39.es/proposal-temporal/#sec-temporal.plaindate.prototype.tozoneddatetime

Bug: v8:11544
Change-Id: I758e46efdc33cfc3f336e5c595a402123ae6c485
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3535920Reviewed-by: Adam Klein <adamk@chromium.org>
Commit-Queue: Frank Tang <ftang@chromium.org>
Cr-Commit-Position: refs/heads/main@{#80709}