RFR: 8306031: Update IANA Language Subtag Registry to Version 2023-04-13 [v3]

[Justin Lu]

> Update the registry and accompanying tests with the **IANA 4/13/2022** update.
> 
> This update introduces the case where an IANA entry can have a preferred value, but that preferred value has a preferred value as well.
> 
> This causes unexpected failures in JDK tests because of how locale equivalencies are created.
> 
> eg: `ar-ajp` has a preferred value of `ajp` but `ajp` has a preferred value of `apc`
> 
> Normally, when the JDK is built, _LocaleEquivlalentMaps.java_ generates the following
> 
> 
> ...
> singleEquivMap.put("ar-ajp", "ajp");
> singleEquivMap.put("ajp", "ar-ajp");
> ...
> multiEquivsMap.put("ajp", new String[] {"apc", "ar-apc"});
> multiEquivsMap.put("apc", new String[] {"ajp", "ar-apc"});
> multiEquivsMap.put("ar-apc", new String[] {"apc", "ajp"});
> ...
> 
> 
> When `LocaleMatcher.parse(ACCEPT_LANGUAGE)` is called with `ACCEPT_LANGUAGE` containing `apc` and `ajp` in that order, the following occurs:
> 
> `apc` is found, `apc` is added, all of `apc's` equivalencies are added: `ajp` and `ar-apc`
> 
> When parse iterates to `ajp`, it finds that it is already added to the list, and does not add it's equivalency `ar-ajp`.
> 
> To address this, the build process must be adjusted so that the equivalencies are built as 
> 
> 
> ...
> multiEquivsMap.put("ajp", new String[] {"apc", "ar-ajp", "ar-apc"});
> multiEquivsMap.put("apc", new String[] {"ajp", "ar-ajp", "ar-apc"});
> multiEquivsMap.put("ar-ajp", new String[] {"apc", "ajp", "ar-apc"});
> multiEquivsMap.put("ar-apc", new String[] {"apc", "ajp", "ar-ajp"});
> ...
> 
> 
> As, if `ar-ajp` has a preferred value of `ajp`, and `ajp` has a preferred value of `apc`, this technically means that `ar-ajp` is equivalent to `apc` and its equivalencies as well. This way, when `LocaleMatcher.parse(ACCEPT_LANGUAGE)` iterates to `apc`, it will add all of it's equivalencies including `ar-ajp`.

Justin Lu has updated the pull request incrementally with one additional commit since the last revision:

  Improve stream processing and hash map creation

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/13501/files
  - new: https://git.openjdk.org/jdk/pull/13501/files/e5d332ee..4a75417f

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=13501&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=13501&range=01-02

  Stats: 15 lines in 1 file changed: 2 ins; 2 del; 11 mod
  Patch: https://git.openjdk.org/jdk/pull/13501.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/13501/head:pull/13501

PR: https://git.openjdk.org/jdk/pull/13501