RFR: 8250984: Memory Docker tests fail on some Linux kernels w/o cgroupv1 …

[Harold Seigel]

Please review this change to fix memory docker tests failures on some Linux kernels w/o cgroupv1 swap limit
capabilities.  The fix works by detecting that swap limit capabilities are not available and returning non-swap related
information.  For example, if memory and swap usage is requested, and swap limit capabilities are not available, then
only memory usage is returned.

The fix was tested by running container tests on systems with and without swap limit capabilities.  Additionally, the
changes were regression tested by running tier1 and tier2 tests on Windows, Linux x64, and Mac OS, and running tier3 -
tier5 tests on Linux x64.

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Commit messages:
 - 8250984: Memory Docker tests fail on some Linux kernels w/o cgroupv1 swap limit capabilities
 - 8250984: Memory Docker tests fail on some Linux kernels w/o cgroupv1 swap limit capabilities

Changes: https://git.openjdk.java.net/jdk/pull/342/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=342&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8250984
  Stats: 115 lines in 8 files changed: 56 ins; 11 del; 48 mod
  Patch: https://git.openjdk.java.net/jdk/pull/342.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/342/head:pull/342

PR: https://git.openjdk.java.net/jdk/pull/342