Question about Handle equality

I was doing some testing and noticed something weird with `stdout`. If I create 2 handles to `stdout`, shouldn't they be considered equal? I saw something similar in #36 so maybe this isn't an issue, but wanted to double check. Since both handles point to 0x2a0 and have a key of None, shouldn't they be considered equal? It's possible I'm missing something obvious, but just wanted to double check.

```rust
let stdout1 = Handle::stdout()?;
let stdout2 = Handle::stdout()?;
assert_eq!(stdout1, stdout2);

assertion `left == right` failed
left: Handle(Handle { kind: Borrowed(HandleRef(HandleRefInner(Some(File { handle: 0x2a0 })))), key: None })
right: Handle(Handle { kind: Borrowed(HandleRef(HandleRefInner(Some(File { handle: 0x2a0 })))), key: None })
```

The issue does not name a source file, test, or entry point. Start by locating Handle's equality implementation and the existing discussion in issue #36, then determine whether equal stdout handles are intended behavior and document or test the resulting semantics.

Written by the indexing model from the issue text.