RFR: 8292250: Create test for co-located JDI MethodEntry, Step, and Breakpoint events

[Chris Plummer]

We currently have no tests for co-located MethodEntry, Step, and Breakpoint events. We should make sure they are being properly co-located as described in the JDI spec, and also do special test cases for [JDK-8292217](https://bugs.openjdk.org/browse/JDK-8292217).

https://docs.oracle.com/en/java/javase/17/docs/api/jdk.jdi/com/sun/jdi/event/EventSet.html

And sorry in advance that the logic is a bit hard to follow in this test due to having multiple test cases, and dealing with the async nature of JDI testing. All I can say is that is used to be a lot worse before I did multiple passes to improve it.

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Commit messages:
 - Make it clear that testcase #1 and #2 failures are ignored.
 - Fix jcheck failures.
 - Add new test for co-located events

Changes: https://git.openjdk.org/jdk/pull/9840/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=9840&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8292250
  Stats: 449 lines in 2 files changed: 449 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/9840.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/9840/head:pull/9840

PR: https://git.openjdk.org/jdk/pull/9840