[8u-dev] Request for review and for approval to backport: 8072466: Deadlock when initializing MulticastSocket and DatagramSocket

[Ivan Gerasimov]

Hello!

I'd like to backport this recent fix from jdk9 to jdk8u-dev.
The fix applies *almost* cleanly after unshuffling.
The only manual editing I had to do was creating 
Java_java_net_DualStackPlainDatagramSocketImpl_initIDs() function in 
DualStackPlainDatagramSocketImpl.c, which didn't exist in jdk8.
All the other changes are the same as in jdk9.

Bug: https://bugs.openjdk.java.net/browse/JDK-8072466
Jdk9 change: http://hg.openjdk.java.net/jdk9/dev/jdk/rev/3884ca98c792
Jdk9 review: 
http://mail.openjdk.java.net/pipermail/core-libs-dev/2015-September/035053.html

Jdk8 webrev: http://cr.openjdk.java.net/~igerasim/8072466/01/webrev/

Would you please review/approve it?

Sincerely yours,
Ivan