RFR: JDK-8328930: [AIX] remove pase related coding

[Matthias Baesken]

We still have quite a lot of OS400 / pase related coding in the hotspot AIX codebase. But this does not work and was never supported in OpenJDK. So we can remove this.

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Commit messages:
 - JDK-8328930

Changes: https://git.openjdk.org/jdk/pull/18471/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=18471&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8328930
  Stats: 419 lines in 8 files changed: 12 ins; 357 del; 50 mod
  Patch: https://git.openjdk.org/jdk/pull/18471.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/18471/head:pull/18471

PR: https://git.openjdk.org/jdk/pull/18471