[jdk16] RFR: 8257906: JFR: RecordingStream leaks memory

[Erik Gahlin]

Backport of JDK-8258478: JFR: RecordingStream leaks memory

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Commit messages:
 - initial

Changes: https://git.openjdk.java.net/jdk16/pull/81/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk16&pr=81&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8257906
  Stats: 55 lines in 4 files changed: 52 ins; 1 del; 2 mod
  Patch: https://git.openjdk.java.net/jdk16/pull/81.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk16 pull/81/head:pull/81

PR: https://git.openjdk.java.net/jdk16/pull/81