JDK 9 RFR of 8177550: (fc) Enable java/nio/channels/FileChannel/{Transfer4GBFile.java, TransferTo6GBFile.java} on Linux and Windows

[Brian Burkhalter]

Please review this test-only change at your convenience.

Issue:	https://bugs.openjdk.java.net/browse/JDK-8177550
Patch:	http://cr.openjdk.java.net/~bpb/8177550/webrev.00/

The test Transfer.java was recently split into three tests and the timeout for all three increased. Therefore we should try re-enabling these tests where they are suppressed on Linux and Windows.

Thanks,

Brian