* gnu/java/net/PlainDatagramSocketImpl.java
	(RECEIVE_LOCK): New member field.
	(SEND_LOCK): New member field.
	(send0): New method.
	(send): Synchronize on SEND_LOCK.
	(receive0): New method.
	(receive): Synchronize on RECEIVE_LOCK.
	* gnu/java/net/natPlainDatagramSocketImplNoNet.cc,
	gnu/java/net/natPlainDatagramSocketImplPosix.cc,
	gnu/java/net/natPlainDatagramSocketImplWin32.cc
	(send0): Renamed from send.
	(receive0): Renamed from receive.

From-SVN: r79579