Only return "subset of" the requested Locales.


Bug: v8:11860
Change-Id: I917753c6f0f5dfc7a52d071febbe03abfab45b04
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2946746Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Frank Tang <ftang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75025}