Verify OpenJDK 8u121: Various sun.nio classes

A collection of non-functional changes to reduce
unnecessary deltas with upstream and add change markers.

Several files will need a second pass - this contains
obvious differences. No functional changes.

Change markers complete:
ojluni/src/main/java/sun/nio/ch/AbstractPollArrayWrapper.java
ojluni/src/main/java/sun/nio/ch/AbstractPollSelectorImpl.java
ojluni/src/main/java/sun/nio/ch/DefaultAsynchronousChannelProvider.java
ojluni/src/main/java/sun/nio/ch/EPoll.java
ojluni/src/main/java/sun/nio/ch/EPollPort.java
ojluni/src/main/java/sun/nio/ch/FileDispatcherImpl.java
ojluni/src/main/java/sun/nio/ch/FileKey.java
ojluni/src/main/java/sun/nio/ch/Invoker.java
ojluni/src/main/java/sun/nio/ch/NativeThread.java
ojluni/src/main/java/sun/nio/ch/Net.java
ojluni/src/main/java/sun/nio/ch/PollArrayWrapper.java
ojluni/src/main/java/sun/nio/ch/SelectionKeyImpl.java
ojluni/src/main/java/sun/nio/ch/ServerSocketChannelImpl.java
ojluni/src/main/java/sun/nio/ch/SocketDispatcher.java
ojluni/src/main/java/sun/nio/ch/ThreadPool.java
ojluni/src/main/java/sun/nio/ch/UnixAsynchronousServerSocketChannelImpl.java
ojluni/src/main/java/sun/nio/ch/UnixAsynchronousSocketChannelImpl.java
ojluni/src/main/java/sun/nio/cs/ThreadLocalCoders.java
ojluni/src/main/java/sun/nio/fs/LinuxNativeDispatcher.java
ojluni/src/main/java/sun/nio/fs/UnixCopyFile.java
ojluni/src/main/java/sun/nio/fs/UnixDirectoryStream.java
ojluni/src/main/java/sun/nio/fs/UnixFileSystemProvider.java
ojluni/src/main/java/sun/nio/fs/UnixNativeDispatcher.java
ojluni/src/main/java/sun/nio/fs/UnixSecureDirectoryStream.java

More to do:
ojluni/src/main/java/sun/nio/ch/DatagramChannelImpl.java
ojluni/src/main/java/sun/nio/ch/FileChannelImpl.java
ojluni/src/main/java/sun/nio/ch/SocketChannelImpl.java
ojluni/src/main/java/sun/nio/fs/LinuxWatchService.java

Bug: 35910877
Test: Build
Change-Id: Ie3453339ae3866c557998ca7af6c70fe611b70d4