RFR: 8318839: Update test thread factory to catch all exceptions [v2]

[Leonid Mesnik]

> The jtreg starts the main thread in a separate ThreadGroup and checks unhandled exceptions for this group. However, it doesn't catch all unhandled exceptions. There is a jtreg issue for this https://bugs.openjdk.org/browse/CODETOOLS-7903526.
> Catching such issues for virtual threads is important because they are not included in any groups. So this fix implements the handler for the test thread factory. 
> 
> A few tests start failing.
> 
> The test
> serviceability/jvmti/HeapMonitor/MyPackage/HeapMonitorVMEventsTest.java
> has testcases for platform and virtual threads. So, there is there's no need to run it with the thread factory.
> 
> The test
> java/lang/Thread/virtual/ThreadAPI.java
> tests UncaughtExceptionHandler and virtual threads. No need to run it with a thread factory.
> 
> Test 
> test/jdk/java/util/concurrent/tck/ThreadTest.java is updated to not check the default empty handler.
> 
> Probably, we need some common approach about dealing with the UncaughtExceptionHandler in jtreg.

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

  Replaced System.exit() with exception.

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/16369/files
  - new: https://git.openjdk.org/jdk/pull/16369/files/8fbb2798..b0878f35

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=16369&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=16369&range=00-01

  Stats: 48 lines in 1 file changed: 37 ins; 10 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/16369.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/16369/head:pull/16369

PR: https://git.openjdk.org/jdk/pull/16369