RFR (XS): 8149596: Remove java.nio.Bits copy wrapper methods

[Mikael Vidstedt]

As part of JDK-8141491[1] the native methods in java.nio.Bits were 
removed, and the functionality is instead provided by the VM through 
j.i.m.Unsafe. The Bits wrapper methods are therefore redundant and can 
be removed.

Bug: https://bugs.openjdk.java.net/browse/JDK-8149596
Webrev: http://cr.openjdk.java.net/~mikael/webrevs/8149596/webrev.00/webrev/

I've run the java/nio jtreg tests and it all passes (modulo a couple of 
unrelated failures).

Cheers,
Mikael


[1] https://bugs.openjdk.java.net/browse/JDK-8141491