* java/nio/channels/Channels.java (newInputStream, newOutputStream):
	Optimize when argument is a FileChannelImpl.
	(newInputStream(FileChannelImpl), newOutputStream(FileChannelImpl)):
	New native methods.
	* java/nio/channels/natChannels.cc:  New file for new native methods.
	* Makefile.am:  Update accordingly.

From-SVN: r78867