[7u-dev] Request for approval for 8012326 : Deadlock occurs when Charset.availableCharsets() is called by several threads at the same time

[Seán Coffey]

Requesting approval to backport this one from JDK 8 where it's been 
soaking for many months.

The change differs slightly with the one found in JDK8. That's discussed 
in the review thread.

bug : https://bugs.openjdk.java.net/browse/JDK-8012326
webrev : http://cr.openjdk.java.net/%7Ecoffeys/webrev.8012326.jdk7u/webrev/
review link : 
http://mail.openjdk.java.net/pipermail/nio-dev/2013-September/002318.html

regards,
Sean.