RFR: 8353053: UserDefinedFileAttributeView not supported on AIX

[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)

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Commit messages:
 - UserDefinedFileAttributeView not supported on AIX
 - UserDefinedFileAttributeView not supported on AIX
 - UserDefinedFileAttributeView not supported on AIX
 - UserDefinedFileAttributeView for AIX

Changes: https://git.openjdk.org/jdk/pull/24276/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=24276&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8353053
  Stats: 118 lines in 6 files changed: 104 ins; 6 del; 8 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