RFR: 8324781: runtime/Thread/TestAlwaysPreTouchStacks.java failed with Expected a higher ratio between stack committed and reserved [v12]

[Liming Liu]

> The testcase failed on Oracle CI since JDK-8315923. The root cause is that Oracle CI runs Linux-5.4.17-UEK where the value of MADV_POPULATE_WRITE (23) is used as MADV_DONTEXEC which is not supported by upstream. This PR solves the testcase failure by checking versions of kernels first, and checking the availability of MADV_POPULATE_WRITE when they are not older than 5.14.

Liming Liu has updated the pull request incrementally with one additional commit since the last revision:

  Fix variable names

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Changes:
  - all: https://git.openjdk.org/jdk/pull/18592/files
  - new: https://git.openjdk.org/jdk/pull/18592/files/5bbeaee9..11167d87

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=18592&range=11
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=18592&range=10-11

  Stats: 5 lines in 1 file changed: 0 ins; 0 del; 5 mod
  Patch: https://git.openjdk.org/jdk/pull/18592.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/18592/head:pull/18592

PR: https://git.openjdk.org/jdk/pull/18592