they are not available.
Make them no-op (or better yet part of public API).

TEST = Build Chromium with V8_SHARED

Review URL: http://codereview.chromium.org/7004051

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7973 ce2b1a6d-e550-0410-aec6-3dcde31c8c00