As of jtreg 7, support for JUnit tests is provided either with `@run junit`, or by leveraging "mixed mode" support in TestNG, whereby TestNG will recognize and invoke JUnit tests.

This "mixed mode" requires declaring a directory of JUnit tests to be in a TestNG directory, using `TestNG.dirs` in a TEST.properties file, and it requires scanning the source files to detect `import org.junit...`

It would be better to be able to avoid the need to use TestNG, and to have jtreg support directories of JUnit tests directly.

Conceptually, this should be as simple as cloning some of the front-end support for TestNG and adapting it for JUnit.