Fix java/lang/ThreadOnSpinWaitProducerConsumer by waiting for consumer thread to finish before restarting trial method.
------------- Commit messages: - 8277659: [TESTBUG] ThreadOnSpinWaitProducerConsumer hangs Changes: https://git.openjdk.java.net/jdk/pull/6560/files Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=6560&range=00 Issue: https://bugs.openjdk.java.net/browse/JDK-8277659 Stats: 1 line in 1 file changed: 1 ins; 0 del; 0 mod Patch: https://git.openjdk.java.net/jdk/pull/6560.diff Fetch: git fetch https://git.openjdk.java.net/jdk pull/6560/head:pull/6560 PR: https://git.openjdk.java.net/jdk/pull/6560
