RFR: 8025293 - JNI exception pending checks in java.net

[Mark Sheppard]

Hi
   please oblige and review the following changes

http://cr.openjdk.java.net/~msheppar/8025293/webrev/

to address the issue in

https://bugs.openjdk.java.net/browse/JDK-8025293

this applies additional checks after JNI native calls in
src/solaris/native/java/net/NetworkInterface.c
src/windows/native/java/net/NetworkInterface.c

The main changes are NULL checks and pending exception checks.

regards
Mark