rustfmt wrap_comments breaks doc tests

[gnzlbg]

Rustfmt with wrap_comments = true and max_width = 79 reformats this:

/// Foo
///
/// ```rust
/// # #![cfg_attr(not(dox),feature(cfg_target_feature, target_feature, stdsimd))]
/// # #[cfg(not(dox))]
/// # #[macro_use]
/// # extern crate stdsimd;
/// ```
fn foo() {}

to this:

/// Foo
///
/// ```rust
/// # #![cfg_attr(not(dox),feature(cfg_target_feature, target_feature,
/// # stdsimd))] # #[cfg(not(dox))]
/// # #[macro_use]
/// # extern crate stdsimd;
/// ```
fn foo() {}

which breaks rust doc because now there are two hashes # # in the second line.

[scampi]

With the latest from master, that won't happen because wrapping is disabled for doc tests #3183

[gnzlbg]

Thanks, I guess we can close this then. Or shall we wait till it hits nightly?

[scampi]

could be good to wait for nightly so people may find it if they get the same problem