CVE-2020-36207: Data races in aovec

The vulnerability stems from Aovec<T> improperly implementing Send and Sync traits without requiring T to implement these traits. In Rust, Send/Sync implementations should only be allowed when the contained type T also satisfies these traits. By unconditionally implementing them, Aovec<T> enables thread-unsafe types (e.g., Rc, Cell) to be used in concurrent contexts, violating Rust's safety guarantees and leading to data races. The root cause is the unsafe trait implementations rather than specific functions, but these trait definitions represent the critical vulnerability points.