Remove TypeKind hack in favor of with_crate_prefix

Author: jyn514

src/librustdoc/passes/collect_intra_doc_links.rs

@@ -847,18 +847,12 @@ impl<'a, 'tcx> DocFolder for LinkCollector<'a, 'tcx> {
 
         // FIXME(jynelson): this shouldn't go through stringification, rustdoc should just use the DefId directly
         let self_name = self_id.and_then(|self_id| {
-            use ty::TyKind;
             if matches!(self.cx.tcx.def_kind(self_id), DefKind::Impl) {
                 // using `ty.to_string()` directly has issues with shortening paths
-                // FIXME: this is a hack, isn't there a better way?
                 let ty = self.cx.tcx.type_of(self_id);
-                let name = match ty.kind() {
-                    TyKind::Adt(def, _) => Some(self.cx.tcx.item_name(def.did).to_string()),
-                    other if other.is_primitive() => Some(ty.to_string()),
-                    _ => None,
-                };
-                debug!("using type_of(): {:?}", name);
-                name
+                let name = ty::print::with_crate_prefix(|| ty.to_string());
+                debug!("using type_of(): {}", name);
+                Some(name)
             } else {
                 let name = self.cx.tcx.opt_item_name(self_id).map(|sym| sym.to_string());
                 debug!("using item_name(): {:?}", name);