Add implementations for Any + Send + Sync
Add implementations for Any + Send + Sync

Implement `is`, `downcast_ref`, `downcast_mut` and `Debug` for
`Any + Send + Sync`.

aidancully/rust,graydon/rust,GBGamer/rust,aidancully/rust,graydon/rust,GBGamer/rust,graydon/rust,GBGamer/rust,aidancully/rust,aidancully/rust,GBGamer/rust,GBGamer/rust,GBGamer/rust,aidancully/rust,GBGamer/rust,GBGamer/rust,graydon/rust,graydon/rust,graydon/rust,aidancully/rust