[foreign][broken build] RFR: Restore JavaNioAccess::newDirectByteBuffer

[Henry Jen]

Hi,

Please review the webrev to fix the build after sync with latest jdk/jdk, where JDK-8193822 removed the function we used to convert a Pointer into a DirectByteBuffer for a similar function in JNI NewDirectByteBuffer.

Also included in the fix to address a reorder warning which fails the build.

http://cr.openjdk.java.net/~henryjen/panama/foreign/8209169/webrev/

Cheers,
Henry