We should perform the illegal redeclaration check earlier so that we do not confuse the AST typer with missing type feedback nodes.

R=yangguo@chromium.org

Review URL: https://codereview.chromium.org/218493007

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@20368 ce2b1a6d-e550-0410-aec6-3dcde31c8c00