RFR: 8371701: Add ability to set NUMA-affinity for threads [v4]

[Joel Sikström]

> Hello,
> 
> This PR adds support for setting the affinity of threads to run on CPUs associated with specific NUMA nodes on Linux. Support for this is needed for [JDK-8371702](https://bugs.openjdk.org/browse/JDK-8371702) to improve performance in the Relocation Phase of ZGC on a NUMA machine.
> 
> Testing:
> * I've run significant performance testing locally on a NUMA machine and performed functional testing to see that the affinity is actually changed. Affinity of a thread can be inspected on Linux using `taskset -cp <tid>`.
> * Running through Oracle's tier1-2

Joel Sikström has updated the pull request incrementally with one additional commit since the last revision:

  Harden comment around user configuration

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/28261/files
  - new: https://git.openjdk.org/jdk/pull/28261/files/125b0132..26765e87

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=28261&range=03
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=28261&range=02-03

  Stats: 5 lines in 1 file changed: 1 ins; 0 del; 4 mod
  Patch: https://git.openjdk.org/jdk/pull/28261.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/28261/head:pull/28261

PR: https://git.openjdk.org/jdk/pull/28261