8085981: java/lang/ProcessHandle/OnExitTest.java: AssertionError: Child onExit not called
Summary: a race condition caused an erroneous fault
Reviewed-by: darcy
8085980: java/lang/ProcessHandle/TreeTest.java: AssertionError: Wrong number of spawned children expected [1] but found [2]
Summary: Modify to expect only the spawned children; enhance debug output
Reviewed-by: darcy