x fmt doesn't format some code

[WaffleLapkin]

While working on rustc I've noticed that x fmt doesn't format some obviously misformatted code.

Here is the code: rust-lang/rust#92164 (comment)

[calebcartwright]

Duplicate of #3863, closing accordingly.

Try manually splitting the string lit so that it's actually possible to fit within the max_width boundary

"the `#[rustc_must_implement_one_of]` attribute must be used with at least 2 method names",