8156512: Mark several tests from java/nio as intermittently failing

Reviewed-by: alanb

jdk/test/java/nio/channels/AsynchronousSocketChannel/Basic.java

@@ -25,7 +25,7 @@
  * @bug 4607272 6842687 6878369 6944810 7023403
  * @summary Unit test for AsynchronousSocketChannel
  * @run main Basic -skipSlowConnectTest
- * @key randomness
+ * @key randomness intermittent
  */
 
 import java.nio.ByteBuffer;

jdk/test/java/nio/channels/FileChannel/InterruptMapDeadlock.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2013, 2016, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -23,6 +23,7 @@
 
 /* @test
  * @bug 8024833
+ * @key intermittent
  * @summary Tests interruption of threads mapping sections of a file channel in
  *   an attempt to deadlock due to nesting of begin calls.
  */