There are at least 4 different JDI tests failing after this change. I'm not 100% sure of the reason for 3 of them, but they all involve I/O related issues, and seem at least partly due to the ThreadStartEvent issuing a ThreadReference.IsVirtual command, and that getting stuck. I wasn't aware of this command being issued when I made the change to use SUSPEND_NONE. So now it is being made while the app continues to run rather than while it is suspended. Also, it is possible for something like a breakpoint to happen before the new thread has been registered with jdb (since all threads are no suspended), and this has the potential to cause problems, so I think it is best to just undo this change. It had good intentions, but is not worth the hassle of the problems it is introducing for tests and jdb.

JDK-8301644 com/sun/jdi/JdbStopThreadTest.java fails after JDK-8300811
JDK-8301695 com/sun/jdi/JdbOptions.java failed with "RuntimeException: waitForPrompt timed out after 240 seconds"
JDK-8301735 Test com/sun/jdi/RedefineG.java timing out on macos
JDK-8301795 com/sun/jdi/RedefineIntConstantToLong.java failed with "waitForPrompt timed out"