[jdk17u-dev] RFR: 8303605: Memory leaks in Metaspace gtests

[Goetz Lindenmaier]

I backport this for parity with 17.0.11-oracle.

I resolved test_virtualspacenode.cpp due to an extra empty line, will mark as clean.

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Commit messages:
 - Backport ddcb369ceabd2207699632e90a358baf251c6f36

Changes: https://git.openjdk.org/jdk17u-dev/pull/2093/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk17u-dev&pr=2093&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8303605
  Stats: 19 lines in 4 files changed: 18 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk17u-dev/pull/2093.diff
  Fetch: git fetch https://git.openjdk.org/jdk17u-dev.git pull/2093/head:pull/2093

PR: https://git.openjdk.org/jdk17u-dev/pull/2093