[jdk11u-dev] RFR: 8230305: Cgroups v2: Container awareness

[Zhengyu Gu]

I would like backport cgroups v2  support to openjdk11u.

The original patch does not apply cleanly, conflicts are resolved manually.

Test:
  - [x] jtreg containers/docker test on Ubuntu 20.04.4 LTS

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Commit messages:
 - Backport d462a6b5c9bd3dae5257cca42ea38c19cb742e3c

Changes: https://git.openjdk.java.net/jdk11u-dev/pull/840/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk11u-dev&pr=840&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8230305
  Stats: 2003 lines in 10 files changed: 1389 ins; 576 del; 38 mod
  Patch: https://git.openjdk.java.net/jdk11u-dev/pull/840.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk11u-dev pull/840/head:pull/840

PR: https://git.openjdk.java.net/jdk11u-dev/pull/840