Request for approval for: 6898310: (cs) Charset cache lookups should be synchronized

[Xueming Shen]

Hi

/Could you please approve the fix for

6898310: (cs) Charset cache lookups should be synchronized
/

This is a forward porting from jdk1.4/5/6u. The same fix has been pushed 
into JDK8.

Webrev is at

http://cr.openjdk.java.net/~sherman/6898310/7u2/webrev

Thanks,
Sherman