RFR: 8307953: [AIX] C locale's font setting was changed by JEP 400 [v2]

[Ichiroh Takiguchi]

> On AIX, lib/fontconfig.bfc file is used to find font setting.
> I ran SwingSet2 List demo program with AIX C locale.
> JDK21's line spacing is larger then JDK17.
> Screen shots are in [JDK-8307953](https://bugs.openjdk.org/browse/JDK-8307953).
> When I used `-Dfile.encoding=COMPAT` option on AIX C locale, SwingSet2 worked fine as expected.
> 
> This situation happens `Charset.defaultCharset()` always returns UTF-8 after JEP 400 by default.
> `native.encoding` system property has platform's encoding/charset name.
> If platform's charset name is not supported by Java, charset name should be `UTF-8`.
> 
> Additionally, following parts are changed:
> `src/java.desktop/aix/data/fontconfig/fontconfig.propertie`s has invalid charset name.
> For Java for AIX:
> - Encoding name for AIX's Zh_TW locale is `big5`, charset name should be `x-IBM950` instead of `big5`.
> - Encoding name for AIX's zh_CN locale is `IBM-eucCN`, charset name should be `x-IBM1383` instead of `x-EUCCN`.
> 
> In my understanding, this fix affects just for AIX platform.
> 
> Note:
> macos-x64 tier1 test was failed, but I think it's not related this PR.

Ichiroh Takiguchi has updated the pull request incrementally with one additional commit since the last revision:

  8307953: [AIX] C locale's font setting was changed by JEP 400

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/13937/files
  - new: https://git.openjdk.org/jdk/pull/13937/files/11b7a5b5..a0b93d2c

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=13937&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=13937&range=00-01

  Stats: 6 lines in 2 files changed: 2 ins; 3 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/13937.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/13937/head:pull/13937

PR: https://git.openjdk.org/jdk/pull/13937