Fix fractional second bug

Cherry pick bug fix in ICU which is needed to support fractional
second format in Intl.DateTimeFormat.
This is needed to launch
https://www.chromestatus.com/feature/5704965743968256
to implement https://github.com/tc39/ecma402/pull/347

Bug: v8:9284, v8:9612, v8:10273
Change-Id: I51c353b25e5ba05a4245c19b654d915171ce0354
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/deps/icu/+/2090433
Reviewed-by: Jungshik Shin <jshin@chromium.org>
7 files changed