RFR: 8349689: Several virtual thread tests missing /native keyword [v4]

[SendaoYan]

> H all,
> 
> This PR add `/native` keyword in the test header for virtual thread tests. The `/native` keyword will make run the related tests by jtreg standalone more friendly.
> 
> I runed all the tests without -nativepath argument and find the fail tests. This will find all the virtual thread tests which missing '/native' flag.
> 
> 1. java/lang/management/ThreadMXBean/VirtualThreads.java#default
> 
> VirtualThreads.java:223 call "invoker()" in test/lib/jdk/test/lib/thread/VThreadPinner.java file, which will call the native function "call".
> java/lang/management/ThreadMXBean/VirtualThreads.java#no-vmcontinuations run this test with VM option "-XX:-VMContinuations" and `assumeTrue(VThreadScheduler.supportsCustomScheduler(), "No support for custom schedulers");` will make junit skip the 'testGetThreadInfoCarrierThread' unit test, so 'VirtualThreads.java#no-vmcontinuations' do not need '/native' keywork.
> 
> 2. java/lang/Thread/virtual/stress/PinALot.java
> 
> PinALot.java:58 call "invoker()" in test/lib/jdk/test/lib/thread/VThreadPinner.java file, which will call the native function "call".
> 
> 3. java/lang/Thread/virtual/SynchronizedNative.java
> 
> Call System.loadLibrary("SynchronizedNative") at line 85.
> 
> 4. Tests java/lang/Thread/virtual/stress/GetStackTraceALotWhenPinned.java, java/lang/Thread/virtual/ThreadAPI.java, java/lang/Thread/virtual/RetryMonitorEnterWhenPinned.java, java/lang/Thread/virtual/MonitorWaitNotify.java, java/lang/Thread/virtual/MonitorPinnedEvents.java, java/lang/Thread/virtual/MonitorEnterExit.java and other tests are similar to java/lang/Thread/virtual/stress/PinALot.java
> 
> 
> - Why we need the '/native' keywork?
> 
> I usually run the tests through jtreg directively, rather than run the tests through make test. If I run the test which load the native shared library files and the test missing '/native' keyword but I forgot to pass the '-nativepath' argument to jtreg, or pass the incorrect '-nativepath' argument to jtreg, sometimes it will report timeouted after a long time, such as java/lang/Thread/virtual/JfrEvents.java. If we add the missing '/native' keywork, jtreg will report 'Error. Use -nativepath to specify the location of native code' right away. So add the missing '/native' keyword will make run the tests more friendly.
> 
> Change has been verified locally, test-fix, no risk.

SendaoYan has updated the pull request incrementally with one additional commit since the last revision:

  update copyright year for test/jdk/java/lang/management/ThreadMXBean/VirtualThreads.java; Split @run line for test/jdk/java/lang/Thread/virtual/ThreadPollOnYield.java

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/23550/files
  - new: https://git.openjdk.org/jdk/pull/23550/files/413ee6b1..07f34357

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=23550&range=03
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=23550&range=02-03

  Stats: 3 lines in 2 files changed: 1 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/23550.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/23550/head:pull/23550

PR: https://git.openjdk.org/jdk/pull/23550