rustfmt-nightly removes blank line between doc comment and crate attribute

[euclio]

I would expect it to leave the blank line.

//! Doc comment

#![attribute]

becomes

//! Doc comment
#![attribute]

[iliekturtles]

Couple more instances where something similar happens:

//! Crate doc comment

// Comment for something else

// no_std
#![cfg_attr(not(feature = "std"), no_std)]

// Another comment.

becomes

//! Crate doc comment
// Comment for something else

// no_std
#![cfg_attr(not(feature = "std"), no_std)]
// Another comment.