dcubed [Fri, 22 Jun 2018 12:15:16 -0400] rev 50718
8205195: NestedThreadsListHandleInErrorHandlingTest fails because hs_err doesn't contain _nested_thread_list_max
Summary: Grab Threads_lock in VMError::controlled_crash() so ErrorHandling tests are more stable.
Reviewed-by: stuefe, sspitsyn