RFR: 8344577: Virtual thread tests are timing out on some macOS systems

[Alan Bateman]

As part of JEP 491, and prep for (e.g. 8336254), we added more tests to test/jdk/java/lang/Thread/virtual to stress several critical areas. A few of these tests can take a long time on older macos-x64 hardware, esp. those with HT enabled as jtreg -concurrency gets computed to a high value. Some of these tests have spinning threads and end up competing with other tests. This directory used to have a TEST.properties with  exclusive.dirs=. to prevent these tests running concurrently with each other but we decided to remove it when the number of tests increased (at one point, tests were waiting several minutes to execute because they couldn't run concurrently with other tests in the directory).

This PR proposes a few adjustments:

- Dial down 3 tests (GetStackTraceALotWhenBlocking, GetStackTraceALotWhenPinned.java, and ParkALot) on macosx-x64. This is done in the test main to avoid doubling the number of test descriptions on these tests.
- Dial down 2 runs of one test (TimedWaitALot #timeout-notify #timeout-interrupt) on all platforms. No change to the other 2 runs of this test.
- Add progress output/tracing to ParkALot.
- Remove "/othervm" from a few tests where that don't need it.

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Commit messages:
 - Initial commit

Changes: https://git.openjdk.org/jdk/pull/22357/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=22357&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8344577
  Stats: 57 lines in 8 files changed: 37 ins; 1 del; 19 mod
  Patch: https://git.openjdk.org/jdk/pull/22357.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/22357/head:pull/22357

PR: https://git.openjdk.org/jdk/pull/22357