ticket:9101: further adjust first-xyz positions to weaker-before nodes

git-svn-id: http://source.icu-project.org/repos/icu/icu@33943 251d0590-4201-4cf1-90de-194747b24ca1
ticket:10253 Plural Rules, work in progress.

git-svn-id: http://source.icu-project.org/repos/icu/icu@33944 251d0590-4201-4cf1-90de-194747b24ca1