Change the code to reflect
https://tc39.github.io/proposal-intl-locale/#sec-canonicalizelocalelist

Bug: v8:8655
Change-Id: I114488dee854b7322a5719de13e4fb8b6f18283c
Reviewed-on: https://chromium-review.googlesource.com/c/1400851
Commit-Queue: Frank Tang <ftang@chromium.org>
Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58808}