8203766: Add some instrumentation to jdk/java/nio/channels/Selector/RacyDeregister.java

[Brian Burkhalter]

https://bugs.openjdk.java.net/browse/JDK-8203766
http://cr.openjdk.java.net/~bpb/8203766/webrev.00/

This test-only change makes the test fail when it reaches 90% of the default timeout period if the test has not either passed or failed already. Hopefully if the test fails in this way there will be more information to corroborate the stack traces from the previously timed out execution. For example there might simply be too many iterations attempted on Windows.

Thanks,

Bria