[jdk21u] RFR: 8313678: SymbolTable can leak Symbols during cleanup

[Oli Gillespie]

Clean backport for https://bugs.openjdk.org/browse/JDK-8313678.

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Commit messages:
 - Backport 4b2703ad39f8160264eb30c797824cc93a6b56e2

Changes: https://git.openjdk.org/jdk21u/pull/73/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk21u&pr=73&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8313678
  Stats: 82 lines in 11 files changed: 53 ins; 14 del; 15 mod
  Patch: https://git.openjdk.org/jdk21u/pull/73.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u.git pull/73/head:pull/73

PR: https://git.openjdk.org/jdk21u/pull/73