RFR[13] JDK-8181386: CipherSpi ByteBuffer to byte array conversion fails for certain data overlap conditions

[Valerie Peng]

Anyone can help review this fix on ByteBuffer input/output encryption?
The fix should be self-explanatory with the comments.

Bug: https://bugs.openjdk.java.net/browse/JDK-8181386

Webrev:http://cr.openjdk.java.net/~valeriep/8181386/webrev.00/ 
<http://cr.openjdk.java.net/~valeriep/8181386/webrev.00/>

Mach5 run is clean.

Thanks,
Valerie