com/sun/jdi/MultiBreakpointsTest.java fails with virtual test thread factory

The test fails when the main debuggee thread is a virtual thread, because virtual threads are always daemon threads. Because of this all the test threads that the debuggee creates are also daemon threads. The main deuggee thread immediately exits after creating the test threads, and at that point there are no non-daemon threads left running to keep the debuggee process alive, so the test threads never get a chance to do all the work that is expected of them.