RFR: 8329596: Add test for virtual threads invoking synchronized native methods

[Alan Bateman]

This is a test-only addition to add a test for virtual threads invoking a synchronized native method and invoking a native method that enter/exits a monitor with JNI MonitorEnter/MonitorExit. The test has been in the loom repo for some time, it can move to the main line in advance of changes to the object monitor implementation.

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Commit messages:
 - Fix typo in comments
 - Initial commit

Changes: https://git.openjdk.org/jdk/pull/18600/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=18600&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8329596
  Stats: 493 lines in 2 files changed: 493 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/18600.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/18600/head:pull/18600

PR: https://git.openjdk.org/jdk/pull/18600