hg: jdk/sandbox: Merge

[magnus.ihse.bursie at oracle.com]

Changeset: 811810e6925d
Author:    ihse
Date:      2018-04-19 21:21 +0200
URL:       http://hg.openjdk.java.net/jdk/sandbox/rev/811810e6925d

Merge

- src/java.base/windows/classes/java/net/TwoStacksPlainSocketImpl.java
- src/java.base/windows/native/libnet/TwoStacksPlainSocketImpl.c
- src/jdk.charsets/share/classes/sun/nio/cs/ext/IBM942C.java
- src/jdk.charsets/share/classes/sun/nio/cs/ext/IBM943C.java