Intra rustdoc links don't work with associated consts

[crumblingstatue]

//! We have here [`foo::MYCONST`] and [`Bar::MYCONST`].

pub mod foo {
	pub const MYCONST: u32 = 42;
}

pub struct Bar;

impl Bar {
	pub const MYCONST: u32 = 42;
}

// Test with non-doc usage

pub const C1: u32 = foo::MYCONST;
pub const C2: u32 = Bar::MYCONST;

Renders as:

rustdoc 1.26.0-nightly (c08480fce 2018-03-23)

Ref #43466