* java/nio/DirectByteBufferImpl.java
	(shiftDown): Made static, give address as argument and
	provide a convenience method that overwrites shiftDown in
	ByteBufferImpl and calls the native shiftDown.
	* java/nio/MappedByteBufferImpl.java
	(): Use optimized method in DirectByteBufferImpl.
	* java/nio/natDirectByteBufferImpl.cc
	(shiftDown): Changed method signature. Removed usage of array_offset.

From-SVN: r80967