[jdk21u] RFR: 8299614: Shenandoah: STW mark should keep nmethod/oops referenced from stack chunk alive

[Aleksey Shipilev]

Clean backport to improve Shenandoah reliability.

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Commit messages:
 - Backport ece9bdfc838a5c419c789319ff794f1ae29b0256

Changes: https://git.openjdk.org/jdk21u/pull/163/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk21u&pr=163&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8299614
  Stats: 63 lines in 15 files changed: 31 ins; 17 del; 15 mod
  Patch: https://git.openjdk.org/jdk21u/pull/163.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u.git pull/163/head:pull/163

PR: https://git.openjdk.org/jdk21u/pull/163