RFR 9: 8065570: (bf spec) ByteBuffer.slice() should make it clear that the initial order is BIG_ENDIAN

[Brian Burkhalter]

Please review at your convenience.

Issue:	https://bugs.openjdk.java.net/browse/JDK-8065570
Patch:	http://cr.openjdk.java.net/~bpb/8065570/webrev.00/

One interesting thing not part of this patch is that the byte order of the ByteBuffer returned by ByteBuffer.asReadOnlyBuffer() is always BIG_ENDIAN, whereas that of the XBuffer returned by XBuffer.asReadOnlyBuffer() is the byte order of the original XBuffer. This seems inconsistent. For instance, this code sequence

        ByteBuffer buf = ByteBuffer.allocate(256);
        buf.order(ByteOrder.LITTLE_ENDIAN);
        System.out.println(buf.asIntBuffer().asReadOnlyBuffer().order());
        System.out.println(buf.asReadOnlyBuffer().asIntBuffer().order());

will print

LITTLE_ENDIAN
BIG_ENDIAN

Thanks,

Brian