and also fix part of test in intl402/Locale/likely-subtags

Improve Intl::ToLanguageTag to also handle -yes in -u- extension
Avoid removing if there are other text after -true and -yes before -

Bug: v8:7669, v8:8236
Change-Id: I59943651889602288e6978d0b1c875d89199fe33
Reviewed-on: https://chromium-review.googlesource.com/c/1383094Reviewed-by: Jungshik Shin <jshin@chromium.org>
Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
Commit-Queue: Frank Tang <ftang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58900}