[jdk17u-dev] RFR: 8275582: Don't purge metaspace mapping lists

[Thomas Stuefe]

I'd like to downport this, since it is a prerequisite for downporting [JDK-8275704](https://bugs.openjdk.org/browse/JDK-8275704)
"Metaspace::contains() should be threadsafe".

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Commit messages:
 - Backport 3ff085e2967508ad312c9d32fa908807aefe69ee

Changes: https://git.openjdk.org/jdk17u-dev/pull/1048/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk17u-dev&pr=1048&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8275582
  Stats: 175 lines in 9 files changed: 13 ins; 156 del; 6 mod
  Patch: https://git.openjdk.org/jdk17u-dev/pull/1048.diff
  Fetch: git fetch https://git.openjdk.org/jdk17u-dev pull/1048/head:pull/1048

PR: https://git.openjdk.org/jdk17u-dev/pull/1048