RFR: 7153107 com/sun/jdi/InterruptHangTest.java fails in nightlies

[Staffan Larsen]

Hi,

For a while we have had various timeout related problem in the JDI tests. The root cause of this seems to be the Indy String Concatenation work which makes stepping over the first string concatenation horrendously slow in debug version of the jdk. It is not ISC itself that is to blame, instead it gets the blame for the full setup of the invokedynamic framework. See JDK-8151887 for a longer discussion about this.

One of the tests that fail because of this is com/sun/jdi/InterruptHangTest.java. In this fix, I have simply increased the timeout that is used internally in the test to take the jtreg timeoutfactor into consideration. This seems to allow enough time for stepping through the indy setup code. 

I have also added timestamped logging to the TestScaffold superclass to make it easier to see what is taking a long time and how far a test has proceeded. 

webrev: http://cr.openjdk.java.net/~sla/7153107/webrev.01/
bug: https://bugs.openjdk.java.net/browse/JDK-7153107

Thanks,
/Staffan