RFR: JDK8U Backport of 8154017: Shutdown hooks are racing against shutdown sequence, if System.exit()-calling thread is interrupted

Hi All, Please review this webrev for jdk8u backport. Webrev: http://cr.openjdk.java.net/~akolarkunnu/8191289/webrev.00/ Main Bug: https://bugs.openjdk.java.net/browse/JDK-8154017 JDK10 review thread: http://mail.openjdk.java.net/pipermail/core-libs-dev/2016-June/041952.html JDK10 changeset: http://hg.openjdk.java.net/jdk9/jdk9/jdk/rev/ceeea7370651 Change w.r.t JDK9 changeset: Changed only throws Exception to throws Throwable in test case, as jdk.testlibrary.ProcessTools.executeProcess() throws Throwable in JDK8. public static void main(String[] args) throws Throwable { Testing: Tested new regression test and all core-libs regression tests on all platforms - there are no new failures. Regards, Muneer