RFR: 8347959: ThreadDumper leaks memory

[Zhengyu Gu]

It leaks _frames array and frames stored inside the array

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Commit messages:
 - 8347959: ThreadDumper leaks memory

Changes: https://git.openjdk.org/jdk/pull/23169/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=23169&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8347959
  Stats: 7 lines in 1 file changed: 6 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/23169.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/23169/head:pull/23169

PR: https://git.openjdk.org/jdk/pull/23169