FileLockImpl.java (fd): Remove field, replacing it by:

	* gnu/java/nio/FileLockImpl.java (fd):  Remove field, replacing it by:
	(ch):  New FileChannelImpl field.  Update constructor to match.
	(releaseImpl):  Remove native method.  Instead ...
	(release):  Call unlock on channel.
	* gnu/java/nio/natFileLockImpl.cc:  Removed file.

From-SVN: r78663