RFR(XXS): 8207913: +EnableTracing crashes on jdk8u

[Liu, Xin]

Hi, Runtime develop,

Could you review this change basing on jdk8u?
Problem: https://bugs.openjdk.java.net/browse/JDK-8207913
Webrev: http://cr.openjdk.java.net/~phh/8207913/webrev.01/

JDK8u has this problem because Thread::current() is NULL when it handles global arguments at startup. OracleJDK8 doesn’t suffer from this issue.
I found jdk12’s counterpart jfrEventClasses.hpp doesn’t have ResourceMark.  Removing it works for both with/without ttyLocker.

We will check in jdk8u/hotspot if reviewers approve it.

Thanks,
--lx