RFR(XXS) 8131331: make new thread dump output line optional

[Daniel D. Daugherty]

Greetings,

The fix for the following bug:

     JDK-8130448 thread dump improvements, comment additions, new
                 diagnostics inspired by 8077392
     https://bugs.openjdk.java.net/browse/JDK-8130448

needs a small tweak in order to pass some internal jstack tests.
This work is tracked by the following bug:

     JDK-8131331 tmtools/jstack/locks/wait_interrupt and wait_notify
                 fail due to wrong number of lock records
     https://bugs.openjdk.java.net/browse/JDK-8131331

Here is the webrev URL:

http://cr.openjdk.java.net/~dcubed/8131331-webrev/0-jdk9-hs-rt/

Testing:

- vm.tmtools Aurora Adhoc run (in process)
- JPRT test job

Thanks, in advance, for any comments, questions or suggestions.

Dan