RFR: 8338365: [PPC64, s390] Out-of-bounds array access in secondary_super_cache

[Amit Kumar]

Port for s390x and PPC for the bug: [JDK-8337958](https://bugs.openjdk.org/browse/JDK-8337958), Out-of-bounds array access in secondary_super_cache

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Commit messages:
 - fix for ppc & s390x

Changes: https://git.openjdk.org/jdk/pull/20578/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=20578&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8338365
  Stats: 6 lines in 2 files changed: 0 ins; 2 del; 4 mod
  Patch: https://git.openjdk.org/jdk/pull/20578.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/20578/head:pull/20578

PR: https://git.openjdk.org/jdk/pull/20578