ticket:10128 IdentifierInfo test, fixed failure from ScriptExtension change to tested chars.

git-svn-id: http://source.icu-project.org/repos/icu/icu/branches/markus@33577 251d0590-4201-4cf1-90de-194747b24ca1
ticket:10128: minor updates to sync with ICU4J

git-svn-id: http://source.icu-project.org/repos/icu/icu/branches/markus@33580 251d0590-4201-4cf1-90de-194747b24ca1
ticket:10128: remove incorrect comment

git-svn-id: http://source.icu-project.org/repos/icu/icu/branches/markus@33582 251d0590-4201-4cf1-90de-194747b24ca1