[jdk21u] RFR: 8315213: java/lang/ProcessHandle/TreeTest.java test enhance output of children

[Matthias Baesken]

8315213: java/lang/ProcessHandle/TreeTest.java test enhance output of children

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Commit messages:
 - Backport f3aeb024d91c2d2088359d261be9a4b56a90663c

Changes: https://git.openjdk.org/jdk21u/pull/192/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk21u&pr=192&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8315213
  Stats: 8 lines in 1 file changed: 5 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jdk21u/pull/192.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u.git pull/192/head:pull/192

PR: https://git.openjdk.org/jdk21u/pull/192