RFR: JDK-8143282: \p{Cn} unassigned code points should be included in \p{C}

[Xueming Shen]

Hi,

Please help review the change for 8143282.

issue: https://bugs.openjdk.java.net/browse/JDK-8143282
webrev: http://cr.openjdk.java.net/~sherman/8143282

thanks,
Sherman