[jdk8u-dev] RFR: 8239785: Cgroups: Incorrect detection logic on old systems in hotspot

[Jonathan Dowland]

This is a backport of add18914fb1294999877b563c734a25b4c17b922 for cgroups v2 support injdk8u-dev, via the 11u backport.

It does not apply clean:

 * context issues for changes made for the different approach for logging in 8u
 * copyright lines

Small amount of re-working of new code that used `log_trace`/`log_debug` to use the 8u approach.

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Depends on: https://git.openjdk.org/jdk8u-dev/pull/130

Commit messages:
 - 8239785: Cgroups: Incorrect detection logic on old systems in hotspot

Changes: https://git.openjdk.org/jdk8u-dev/pull/135/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk8u-dev&pr=135&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8239785
  Stats: 707 lines in 6 files changed: 534 ins; 100 del; 73 mod
  Patch: https://git.openjdk.org/jdk8u-dev/pull/135.diff
  Fetch: git fetch https://git.openjdk.org/jdk8u-dev pull/135/head:pull/135

PR: https://git.openjdk.org/jdk8u-dev/pull/135