Incorrect dyn addition for `Trait + 'a` (Rust 2015)

[ksqsf]

#![allow(unused)]

mod sub {
    pub trait Trait {}
}

struct T;
impl ::sub::Trait for T {}

fn main() {
    use ::std::sync::Arc;
    let p : Arc<::sub::Trait + 'static>;
}

In the code above, rustfix cannot figure out how to add dyn with parentheses, complaining:

The following errors were reported:
error[E0433]: failed to resolve: use of undeclared type or module `dyn`
  --> src/lib.rs:12:17
   |
12 |     let p : Arc<dyn ::sub::Trait + 'static>;
   |                 ^^^ use of undeclared type or module `dyn`

warning: trait objects without an explicit `dyn` are deprecated
  --> src/lib.rs:12:17
   |
12 |     let p : Arc<dyn ::sub::Trait + 'static>;
   |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn dyn ::sub::Trait + 'static`
   |
   = note: `#[warn(bare_trait_objects)]` on by default

When used with --broken-code enabled, it simply adds a dyn without parentheses, effectively breaking the code.

[ehuss]

Thanks for the report! This is a known issue tracked in rust-lang/rust#63330.