[jdk17u-dev] RFR: 8275704: Metaspace::contains() should be threadsafe

[Thomas Stuefe]

Makes Metaspace::contains() threadsafe by adding fences to VS list node walking.

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Commit messages:
 - Backport d9b0138d7d02ceddc5d9c73908177f0b0d2e7c54

Changes: https://git.openjdk.org/jdk17u-dev/pull/1120/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk17u-dev&pr=1120&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8275704
  Stats: 23 lines in 2 files changed: 15 ins; 1 del; 7 mod
  Patch: https://git.openjdk.org/jdk17u-dev/pull/1120.diff
  Fetch: git fetch https://git.openjdk.org/jdk17u-dev pull/1120/head:pull/1120

PR: https://git.openjdk.org/jdk17u-dev/pull/1120