reorder_impl_items doesn't maintain newlines

[TornaxO7]

Reproduction information

Example code:

pub struct BeautifulStruct;

impl BeautifulStruct {

    /// Another awesome doc
    const LMAO: i32 = 42;

    /// Awesome doc
    const ROFL: i32 = 10;
}

fn main() {
    println!("Hello, world!");
}

Content of ~/.config/rusfmt/rustfmt.toml:

reorder_impl_items = true

Output of rustfmt -V: rustfmt 1.4.37-nightly (7c3872e 2021-06-24)

Problem

If I run rustfmt with the settings and the file above, rustfmt changes the file to this:

pub struct BeautifulStruct;

impl BeautifulStruct {
    /// Another awesome doc
    const LMAO: i32 = 42;
    /// Awesome doc
    const ROFL: i32 = 10;
}

fn main() {
    println!("Hello, world!");
}

But I'd expect to be like this:

pub struct BeautifulStruct;

impl BeautifulStruct {
    /// Another awesome doc
    const LMAO: i32 = 42;

    /// Awesome doc
    const ROFL: i32 = 10;
}

fn main() {
    println!("Hello, world!");
}

If you don't see the difference: There's a blank line between const LMAO: i32 = 42; and the documentation paragraph /// Awesome doc in my "expectation-example".

[ytmimi]

Linking tracking issue for reorder_impl_items #3363