RFR JDK-8158482: regex UNICODE_CHARACTER_CLASS flag cannot be disabled with an embedded flag expression

[Xueming Shen]

Hi,

Please review the change for JDK-8158482. It appears a "break" is
missing from the implementation.

issue: https://bugs.openjdk.java.net/browse/JDK-8158482
webrev: http://cr.openjdk.java.net/~sherman/8158482

Thanks,
Sherman