Implement Debug for ptr::Shared and ptr::Unique.
Implement Debug for ptr::Shared and ptr::Unique.

Fixes https://github.com/rust-lang/rust/issues/46755.

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