RFR JDK-8205540: hotspot/jtreg/vmTestbase/nsk/jdb/trace/trace001/trace001.java fails with Debuggee did not exit after 15 <cont> commands

[Peter Levart]

Please review the following tiny change that delays 
TerminatingThreadLocal class initialization until the 1st thread that 
actually uses thread locals, exits:

http://cr.openjdk.java.net/~plevart/jdk-dev/8205540_TerminatingThreadLocal.opt/webrev.01/

Since JDK-8202788 has been pushed, a hotspot/jdb test started failing:

     https://bugs.openjdk.java.net/browse/JDK-8205540

...presumably because it is not expecting so many instructions to be 
executed at thread exit. This patch might help silence the test. Even if 
it doesn't silence the test, it is a change that delays one class 
initialization until it is needed and this is good.

Regards, Peter