[jdk25u-dev] RFR: 8354894: java/lang/Thread/virtual/Starvation.java timeout on server with high CPUs

[Roland Mesde]

Backporting JDK-8354894: java/lang/Thread/virtual/Starvation.java timeout on server with high CPUs

For parity with Oracle JDK. Fix adjusts iteration count by dividing by CPU core count, and removed timeout=800 as default 120 timeout is now sufficient. 

Merge conflict (resolved) was the change in the timeout.

Ran GHA Sanity Checks (passed), jtreg tier1 tests (passed) and related tests (passed) on linux-x64, linux-aarch64, macos-aarch64 and windows-x64. Also ran a test on an EC2 instance (linux-x64) with high cpu count (r5dn.24xlarge - 96 core) and it finished under 1s:

(Passed) - make test-tier1
(Passed) - make test TEST=test/jdk/java/lang/Thread/virtual/Starvation.java

Results are attached.

[linux-x64-96-core-test.log](https://github.com/user-attachments/files/23911957/linux-x64-96-core-test.log)

[linux-aarch64-jtreg-tier1.log](https://github.com/user-attachments/files/23911996/linux-aarch64-jtreg-tier1.log)
[linux-aarch64-specific-test.log](https://github.com/user-attachments/files/23911997/linux-aarch64-specific-test.log)
[linux-x64-jtreg-tier1.log](https://github.com/user-attachments/files/23911998/linux-x64-jtreg-tier1.log)
[linux-x64-specific-test.log](https://github.com/user-attachments/files/23911999/linux-x64-specific-test.log)
[macos-aarch64-jtreg-tier1.log](https://github.com/user-attachments/files/23912000/macos-aarch64-jtreg-tier1.log)
[macos-aarch64-specific-test.log](https://github.com/user-attachments/files/23912001/macos-aarch64-specific-test.log)
[windows-x64-jtreg-tier1.log](https://github.com/user-attachments/files/23912002/windows-x64-jtreg-tier1.log)
[windows-x64-specific-test.log](https://github.com/user-attachments/files/23912003/windows-x64-specific-test.log)

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Commit messages:
 - Backport 0366d8823bc844225ca24964e352ce0a57d01683

Changes: https://git.openjdk.org/jdk25u-dev/pull/49/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk25u-dev&pr=49&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8354894
  Stats: 10 lines in 1 file changed: 7 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jdk25u-dev/pull/49.diff
  Fetch: git fetch https://git.openjdk.org/jdk25u-dev.git pull/49/head:pull/49

PR: https://git.openjdk.org/jdk25u-dev/pull/49