[jdk21u] RFR: 8351500: G1: NUMA migrations cause crashes in region allocation

[Thomas Stuefe]

This pull request contains a backport of commit [37ec7962](https://github.com/openjdk/jdk/commit/37ec796255ae857588a5c7e0d572407dd81cbec9) from the [openjdk/jdk](https://git.openjdk.org/jdk) repository.

The commit being backported was authored by Thomas Stuefe on 13 Mar 2025 and was reviewed by Roman Kennke, Stefan Johansson and Thomas Schatzl.

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Please consider this patch for backporting. It fixes a G1 crash we see at a customer with a very large NUMA installation.

The patch applied cleanly, but for JDK 21 it was not sufficient to fix the bug. In JDK 21, we must also fix `G1Allocator::attempt_allocation_force`.

Reviewer Notes: Unfortunately, the upstream patch was tainted with a couple of aesthetic code changes (changes to parameter order) due to the wishes of the G1 maintainers. These changes are harmless but obfuscate the real issue that is fixed.

The heart of this patch is in `G1CollectedHeap::attempt_allocation` and everything that happens below that frame, in particular `G1CollectedHeap::attempt_allocation_slow`. Where before we would retrieve the current node number for the current CPU we are running on over and over again - which exposes us to bugs when that node number changes mid-function, we now determine the node number once, up in `G1CollectedHeap::attempt_allocation`, and use that one throughout the allocation process.

The original patch is commit 0aebb171b7e0d9aecb04a5f9832620898047674f, whereas the JDK-21 specific additions are in follow-up commit f57033d6ce60fcca3ee4e9f3cfa0dc3d8d365cc0.

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Testing: 

- I tested the fix with an additional change mimicking tons of NUMA node migrations. I verified that without the fix, we get the crashes/asserts our customer sees; with patch, crashes/asserts are gone.
- SAP was nice enough to run their whole JDK21 testing CI, all green
- I am running tier1_gc on Linux x64
- GHAs green

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Commit messages:
 - JDK-21-specific additions
 - Backport 37ec796255ae857588a5c7e0d572407dd81cbec9

Changes: https://git.openjdk.org/jdk21u/pull/461/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk21u&pr=461&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8351500
  Stats: 57 lines in 5 files changed: 17 ins; 12 del; 28 mod
  Patch: https://git.openjdk.org/jdk21u/pull/461.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u.git pull/461/head:pull/461

PR: https://git.openjdk.org/jdk21u/pull/461