RFR: Merge jdk8u:master

[Andrew John Hughes]

Merge jdk8u372-b06

GHA builds will not work until [JDK-8293107](https://bugs.openjdk.org/browse/JDK-8293107) is merged in 8u462-b01

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Commit messages:
 - Merge jdk8u372-b06
 - 8304053: Revert os specific stubs for SystemMetrics
 - 8303828: [Solaris] Broken jdk8u build after JDK-8266391

The merge commit only contains trivial merges, so no merge-specific webrevs have been generated.

Changes: https://git.openjdk.org/shenandoah-jdk8u/pull/45/files
  Stats: 67 lines in 4 files changed: 4 ins; 62 del; 1 mod
  Patch: https://git.openjdk.org/shenandoah-jdk8u/pull/45.diff
  Fetch: git fetch https://git.openjdk.org/shenandoah-jdk8u.git pull/45/head:pull/45

PR: https://git.openjdk.org/shenandoah-jdk8u/pull/45