Also remove the obsolte __GNUC_VERSION__ #define.

R=svenpanne@chromium.org

Review URL: https://codereview.chromium.org/23522003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@16385 ce2b1a6d-e550-0410-aec6-3dcde31c8c00