RFR: 8353953: con/sun/jdi tests should be fixed to not always require includevirtualthreads=y

[Chris Plummer]

Don't use includevirtualthreads=y unless the test requires it. Debuggers don't usually use includevirtualthreads=y, so we should be doing most of our testing without it. The only reason tests use it is because some tests need it so they can find virtual threads in the debuggee by using vm.allThreads(). This change limits the use of includevirtualthreads=y to just those com/sun/jdi tests that need it.

Tested by running com/sun/jdi tests on all supported platforms in both platform threads mode and virtual threads mode. Also tested with tier1 CI.

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Commit messages:
 - Don't use includevthreads=y unless the test requires it.

Changes: https://git.openjdk.org/jdk/pull/24583/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=24583&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8353953
  Stats: 16 lines in 4 files changed: 9 ins; 0 del; 7 mod
  Patch: https://git.openjdk.org/jdk/pull/24583.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/24583/head:pull/24583

PR: https://git.openjdk.org/jdk/pull/24583