Merged r14045 into trunk branch.

Fix bugs in previous_ast_id tracking

R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/12893017

git-svn-id: https://v8.googlecode.com/svn/trunk@14054 ce2b1a6d-e550-0410-aec6-3dcde31c8c00