[jdk21u-dev] RFR: 8364258: ThreadGroup constant pool serialization is not normalized

[Johannes Bechberger]

This is a backport of JDK-8364258: ThreadGroup constant pool serialization is not normalized

The original patch didn't apply cleanly because of CPU-time sampler related changes in the same code areas that came in with JDK 25.

Tested it in SapMachine's internal queue.

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Commit messages:
 - Backport 1e2bf070f0cb9e852839347d1f5711c583091d85

Changes: https://git.openjdk.org/jdk21u-dev/pull/2373/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk21u-dev&pr=2373&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8364258
  Stats: 939 lines in 12 files changed: 436 ins; 483 del; 20 mod
  Patch: https://git.openjdk.org/jdk21u-dev/pull/2373.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u-dev.git pull/2373/head:pull/2373

PR: https://git.openjdk.org/jdk21u-dev/pull/2373