JDK 8 RFR 8010371: getaddrinfo can fail with EAI_SYSTEM/EAGAIN, causes UnknownHostException to be thrown

[Brian Burkhalter]

Hello net-dev members,

Please review this proposed fix at your convenience.

Summary
When looking up a host and an EAGAIN error is encountered, throw an instance of the new HostLookupException subclass of UnknownHostException.

Issue
https://bugs.openjdk.java.net/browse/JDK-8010371

Webrev
http://cr.openjdk.java.net/~bpb/8010371

If this fix appears acceptable I will file a CCC request.

Thanks,

Brian