A64: Replace a Cmp/Branch sequence by a conditional compare.

R=jochen@chromium.org, ulan@chromium.org

Review URL: https://codereview.chromium.org/169403003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@19472 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
A64: Remove early_exit unused mechanism in CompareMap.

R=jochen@chromium.org, ulan@chromium.org

Review URL: https://codereview.chromium.org/169733003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@19473 ce2b1a6d-e550-0410-aec6-3dcde31c8c00