RFR: 8353053: (fs) Add support for UserDefinedFileAttributeView on AIX [v2]

[Varada M]

> In AIX, the JFS2 supports extended attributes which has fgetea, fsetea, flistea, femoveea APIs support fetching, setting, listing and removing extended attributes. 
> 
> JBS: [JDK-8353053](https://bugs.openjdk.org/browse/JDK-8353053)

Varada M 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 five additional commits since the last revision:

 - Merge branch 'openjdk:master' into basic.java
 - UserDefinedFileAttributeView not supported on AIX
 - UserDefinedFileAttributeView not supported on AIX
 - UserDefinedFileAttributeView not supported on AIX
 - UserDefinedFileAttributeView for AIX

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/24276/files
  - new: https://git.openjdk.org/jdk/pull/24276/files/38b140f8..6866e532

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=24276&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=24276&range=00-01

  Stats: 56663 lines in 1700 files changed: 14104 ins; 35720 del; 6839 mod
  Patch: https://git.openjdk.org/jdk/pull/24276.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/24276/head:pull/24276

PR: https://git.openjdk.org/jdk/pull/24276