A64: Now that we have veneers, fix a couple of branches to directly jump to their target.

R=ulan@chromium.org

Review URL: https://codereview.chromium.org/207883002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@20169 ce2b1a6d-e550-0410-aec6-3dcde31c8c00