Spec Text:
https://tc39.es/proposal-temporal/#sec-temporal.plainyearmonth.compare
https://tc39.es/proposal-temporal/#sec-temporal.plainmonthday.compare
https://tc39.es/proposal-temporal/#sec-temporal.plainmonthday.prototype.equals

Bug: v8:11544
Change-Id: Ia03946e0e183ec9b0a8130515607c29a32a8b265
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3673418Reviewed-by: Adam Klein <adamk@chromium.org>
Commit-Queue: Frank Tang <ftang@chromium.org>
Cr-Commit-Position: refs/heads/main@{#80986}