<i18n dev> RFR: 8174269: Remove COMPAT locale data provider from JDK [v6]

[Naoto Sato]

> This PR intends to remove the legacy `COMPAT` locale data from the JDK. The `COMPAT` locale data was introduced for applications' migratory purposes transitioning to `CLDR`. It is becoming a technical debt and now is the time to remove it (we've been emitting a warning at JVM startup since JDK21, if the app is using `COMPAT`). A corresponding CSR has also been drafted.

Naoto Sato has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains 44 additional commits since the last revision:

 - Merge branch 'master' into JDK-8174269-COMPAT-Removal
 - Addressing review comments
 - Update test/jdk/java/text/Format/DateFormat/Bug6683975.java
   
   Co-authored-by: Justin Lu <Justin.lu at oracle.com>
 - Remove `GensrcLocaleData.gmk`
 - Update make/jdk/src/classes/build/tools/cldrconverter/CLDRConverter.java
   
   Co-authored-by: Andrey Turbanov <turbanoff at gmail.com>
 - cleanup
 - BreakIteratorProvider available locales fix
 - clean-up
 - test fixes
 - makeZoneData.pl fix
 - ... and 34 more: https://git.openjdk.org/jdk/compare/fe877cfd...b771e303

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Changes:
  - all: https://git.openjdk.org/jdk/pull/17991/files
  - new: https://git.openjdk.org/jdk/pull/17991/files/d5953788..b771e303

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=17991&range=05
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=17991&range=04-05

  Stats: 19239 lines in 1290 files changed: 10762 ins; 3853 del; 4624 mod
  Patch: https://git.openjdk.org/jdk/pull/17991.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/17991/head:pull/17991

PR: https://git.openjdk.org/jdk/pull/17991