Remove disambiguators from link text

Related to https://github.com/rust-lang/rust/issues/65354

- Pass through the replacement text to `markdown.rs`
- Add some tests
- Add a state machine that actually replaces the text when parsing Markdown

src/librustdoc/html/render/mod.rs

@@ -64,8 +64,7 @@ use serde::ser::SerializeSeq;
 use serde::{Serialize, Serializer};
 
 use crate::clean::{self, AttributesExt, Deprecation, GetDefId, RenderedLink, SelfTy, TypeKind};
-use crate::config::RenderInfo;
-use crate::config::RenderOptions;
+use crate::config::{RenderInfo, RenderOptions};
 use crate::docfs::{DocFS, PathError};
 use crate::doctree;
 use crate::error::Error;