[8u] RFR: 8225435: Upgrade IANA Language Subtag Registry to the latest for JDK14

[Severin Gehwolf]

Hi,

Please review this change to update the language subtags in OpenJDK 8u.
A similar change has been done to Oracle JDK a few releases back.

The JDK 11 patch applies cleanly, but the test fails to compile due to
use of List.of(). I've changed it to use
Collections.unmodifiableList(Arrays.asList(...)) instead.

Bug: https://bugs.openjdk.java.net/browse/JDK-8225435
webrev: https://cr.openjdk.java.net/~sgehwolf/webrevs/JDK-8225435/02/webrev/

Testing: modified regression test (fails before; passes after). tier1 (no changes).

Thoughts?

Thanks,
Severin