Unify function parameter checking in PreParser and Parser.

This also makes the "delayed strict mode violations" mechanism in PreParser
unnecessary.

The attached tests didn't pass before this CL but now they do.

BUG=v8:3126
LOG=N
R=mstarzinger@chromium.org

Review URL: https://codereview.chromium.org/157453003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@19197 ce2b1a6d-e550-0410-aec6-3dcde31c8c00