roll another resolution logic in rustdoc

src/librustdoc/clean/mod.rs

@@ -1381,7 +1381,8 @@ fn clean_qpath<'tcx>(hir_ty: &hir::Ty<'tcx>, cx: &mut DocContext<'tcx>) -> Type
                 ty::Projection(proj) => Res::Def(DefKind::Trait, proj.trait_ref(cx.tcx).def_id),
                 // Rustdoc handles `ty::Error`s by turning them into `Type::Infer`s.
                 ty::Error(_) => return Type::Infer,
-                _ => bug!("clean: expected associated type, found `{:?}`", ty),
+                // Otherwise, this is an inherent associated type.
+                _ => return clean_middle_ty(ty, cx, None),
             };
             let trait_ = clean_path(&hir::Path { span, res, segments: &[] }, cx);
             register_res(cx, trait_.res);

src/test/rustdoc-ui/ambiguous-inherent-assoc-ty.rs

@@ -1,3 +1,4 @@
+// check-pass
 // This test ensures that rustdoc does not panic on inherented associated types
 // that are referred to without fully-qualified syntax.
 
@@ -9,8 +10,4 @@ pub struct Struct;
 impl Struct {
     pub type AssocTy = usize;
     pub const AssocConst: Self::AssocTy = 42;
-    //~^ ERROR ambiguous associated type
-    //~| HELP use fully-qualified syntax
-    //~| ERROR ambiguous associated type
-    //~| HELP use fully-qualified syntax
 }