JDK RFR of 8054720: Modifications of I/O methods for instrumentation purposes

[Brian Burkhalter]

JDK 9 reviewers:

I would like to request the review of this patch to address the indicated issue:

Issue:	https://bugs.openjdk.java.net/browse/JDK-8054720
Patch:	http://cr.openjdk.java.net/~bpb/8054720/

This changes passes the jdk_io and jdk_net tests on all platforms.

Thanks,

Brian