Cherry-pick 3 locale fixes

Locale has bugs related to grandfather tag processing.
This block the v8 Intl.Locale launch.

Upstream bugs:
  https://unicode-org.atlassian.net/browse/ICU-20187
  https://unicode-org.atlassian.net/browse/ICU-20407
  https://unicode-org.atlassian.net/browse/ICU-20410
  https://unicode-org.atlassian.net/browse/ICU-20411
Upstream fixes:
  https://github.com/unicode-org/icu/pull/418
  https://github.com/unicode-org/icu/pull/414
  https://github.com/unicode-org/icu/pull/416

Bug: 913298,v8:8260,v8:8242
Test: In v8, fix intl402/Locale/constructor-non-iana-canon
Test: v8: intl402/Locale/constructor-tag, and intl402/Locale/likely-subtags-grandfathered
Change-Id: Ifcff754587bba75413987729fac8f563ba5e75e0
Reviewed-on: https://chromium-review.googlesource.com/c/1476117
Reviewed-by: Jungshik Shin <jshin@chromium.org>