[jdk21u-dev] RFR: 8324817: Parallel GC does not pre-touch all heap pages when AlwaysPreTouch enabled and large page disabled

[Liang Mao]

Clean backport of fix of pretouch for parallel gc. The original issue is reproduced with linux/aarch64 and fix is verified.

Additional testing:
 - [x] Linux aarch64 server release/fastdebug, `hotspot_gc` with `-XX:+UseParallelGC -XX:+AlwaysPreTouch`

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Commit messages:
 - Backport 80642dd7af3fcc7c042f11798c5cc899e20b9368

Changes: https://git.openjdk.org/jdk21u-dev/pull/280/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk21u-dev&pr=280&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8324817
  Stats: 83 lines in 2 files changed: 81 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk21u-dev/pull/280.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u-dev.git pull/280/head:pull/280

PR: https://git.openjdk.org/jdk21u-dev/pull/280