RFR: 8305608: Change VMConnection to use "test.class.path"instead of "test.classes" [v3]

[Leonid Mesnik]

> Currently, VMConnection run debugee using "test.classes" as a classpath. It cause test failures when virtual thread factory (wrapper) is enabled and test is not located the same directory as TestScaffold.

Leonid Mesnik has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains four commits:

 - Merge branch 'master' of https://github.com/openjdk/jdk into 8305608
 - fix
 - more tests are added
 - updated vmconnection

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

Changes: https://git.openjdk.org/jdk/pull/13339/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=13339&range=02
  Stats: 19 lines in 2 files changed: 1 ins; 12 del; 6 mod
  Patch: https://git.openjdk.org/jdk/pull/13339.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/13339/head:pull/13339

PR: https://git.openjdk.org/jdk/pull/13339