_exiting_threads_count, _exiting_daemon_threads_count, _daemon_threads_count, _live_threads_count
These four variables are changed together under Threads_lock, but we read them without Threads_lock.

get_live_thread_count/get_daemon_thread_count sometimes return a negative value, e.g if you first load _daemon_threads_count => several threads then starting to exiting, when you load _exiting_daemon_threads_count it can be larger, and we return a negative number.

TEST FAILED: Minimal number of daemon thread count is 21ThreadMXBean.getDaemonThreadCount() returned 15
TEST FAILED: Minimal number of daemon thread count is 21ThreadMXBean.getDaemonThreadCount() returned 15
TEST FAILED: Minimal number of daemon thread count is 0ThreadMXBean.getDaemonThreadCount() returned -6
TEST FAILED: Minimal number of daemon thread count is 0ThreadMXBean.getDaemonThreadCount() returned -6
TEST FAILED: Minimal number of daemon thread count is 0ThreadMXBean.getDaemonThreadCount() returned -6
TEST FAILED: Minimal number of daemon thread count is 0ThreadMXBean.getDaemonThreadCount() returned -6