RFR: 8353955: nsk/jdi tests should be fixed to not always require includevirtualthreads=y [v6]

[Chris Plummer]

> What this PR is fixing is the issue with all of our nsk/jdi testing being done with includevirtualthreads=y even though debuggers typically use the default includevirtualthreads=n. As a result we have a testing gap with includevirtualthreads=n.
> 
> includevirtualthreads=y forces the debug agent to track all virtual threads so they are returned by vm.allThreads(). Some tests need this since they use vm.allThreads() to find the debuggee threads. Without includevirtualthreads=y, vm.allThreads() usually won't return any virtual threads (although it might return some for which events have been triggered).
> 
> There are nearly 1200 nsk/jdi tests. There were about 350 tests that actually needed includevirtualthreads=y, but most of these have been addressed by other PRs, leaving the 20 or so tests being addressed in this PR. With this PR now defaulting to includevirtualthreads=n, the tests that require includevirtualthreads=y need to override the default by specifying the -includevirtualthreads @run option.

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

  remove mistaken edit

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Changes:
  - all: https://git.openjdk.org/jdk/pull/24606/files
  - new: https://git.openjdk.org/jdk/pull/24606/files/7aa6b518..599aae6c

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=24606&range=05
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=24606&range=04-05

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/24606.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/24606/head:pull/24606

PR: https://git.openjdk.org/jdk/pull/24606