6993267: TEST_BUG: java/nio/file/Path/InterruptCopy.java fails intermittently (win)

[Alan Bateman]

This test exercises copyTo with an implementation specific option that 
allows the copy to be interrupted. It fails intermittently on some of 
our faster Windows machines because the copy completes before it can be 
interrupted. The follow webrev fixes the test to make it more robust and 
handle the case where the copy completes quickly.
  http://cr.openjdk.java.net/~alanb/6993267/webrev/

Thanks,
Alan.