Fix method dispatch in Keyed/StoreIC, and JumpIfNotUniqueName usage

R=ishell@chromium.org

Review URL: https://codereview.chromium.org/592113002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24139 ce2b1a6d-e550-0410-aec6-3dcde31c8c00