Fix private intra-doc warnings on associated items

The issue was that the `kind, id` override was previously only being
considered for the disambiguator check, not the privacy check. This uses
the same ID for both.

src/librustdoc/passes/collect_intra_doc_links.rs

@@ -1151,11 +1151,12 @@ impl LinkCollector<'_, '_> {
         };
 
         let verify = |kind: DefKind, id: DefId| {
-            debug!("intra-doc link to {} resolved to {:?}", path_str, res);
+            let (kind, id) = self.kind_side_channel.take().unwrap_or((kind, id));
+            debug!("intra-doc link to {} resolved to {:?} (id: {:?})", path_str, res, id);
 
             // Disallow e.g. linking to enums with `struct@`
             debug!("saw kind {:?} with disambiguator {:?}", kind, disambiguator);
-            match (self.kind_side_channel.take().map(|(kind, _)| kind).unwrap_or(kind), disambiguator) {
+            match (kind, disambiguator) {
                 | (DefKind::Const | DefKind::ConstParam | DefKind::AssocConst | DefKind::AnonConst, Some(Disambiguator::Kind(DefKind::Const)))
                 // NOTE: this allows 'method' to mean both normal functions and associated functions
                 // This can't cause ambiguity because both are in the same namespace.
@@ -1190,7 +1191,7 @@ impl LinkCollector<'_, '_> {
                 }
             }
 
-            Some((kind, id))
+            Some(())
         };
 
         match res {
@@ -1241,7 +1242,7 @@ impl LinkCollector<'_, '_> {
                 Some(ItemLink { link: ori_link.link, link_text, did: None, fragment })
             }
             Res::Def(kind, id) => {
-                let (kind, id) = verify(kind, id)?;
+                verify(kind, id)?;
                 let id = clean::register_res(cx, rustc_hir::def::Res::Def(kind, id));
                 Some(ItemLink { link: ori_link.link, link_text, did: Some(id), fragment })
             }

src/test/rustdoc-ui/intra-doc/private.private.stderr

@@ -1,11 +1,19 @@
 warning: public documentation for `DocMe` links to private item `DontDocMe`
   --> $DIR/private.rs:5:11
    |
-LL | /// docs [DontDocMe]
+LL | /// docs [DontDocMe] [DontDocMe::f]
    |           ^^^^^^^^^ this item is private
    |
    = note: `#[warn(private_intra_doc_links)]` on by default
    = note: this link resolves only because you passed `--document-private-items`, but will break without
 
-warning: 1 warning emitted
+warning: public documentation for `DocMe` links to private item `DontDocMe::f`
+  --> $DIR/private.rs:5:23
+   |
+LL | /// docs [DontDocMe] [DontDocMe::f]
+   |                       ^^^^^^^^^^^^ this item is private
+   |
+   = note: this link resolves only because you passed `--document-private-items`, but will break without
+
+warning: 2 warnings emitted
 

src/test/rustdoc-ui/intra-doc/private.public.stderr

@@ -1,11 +1,19 @@
 warning: public documentation for `DocMe` links to private item `DontDocMe`
   --> $DIR/private.rs:5:11
    |
-LL | /// docs [DontDocMe]
+LL | /// docs [DontDocMe] [DontDocMe::f]
    |           ^^^^^^^^^ this item is private
    |
    = note: `#[warn(private_intra_doc_links)]` on by default
    = note: this link will resolve properly if you pass `--document-private-items`
 
-warning: 1 warning emitted
+warning: public documentation for `DocMe` links to private item `DontDocMe::f`
+  --> $DIR/private.rs:5:23
+   |
+LL | /// docs [DontDocMe] [DontDocMe::f]
+   |                       ^^^^^^^^^^^^ this item is private
+   |
+   = note: this link will resolve properly if you pass `--document-private-items`
+
+warning: 2 warnings emitted
 

src/test/rustdoc-ui/intra-doc/private.rs

@@ -2,8 +2,13 @@
 // revisions: public private
 // [private]compile-flags: --document-private-items
 
-/// docs [DontDocMe]
+/// docs [DontDocMe] [DontDocMe::f]
 //~^ WARNING public documentation for `DocMe` links to private item `DontDocMe`
+//~| WARNING public documentation for `DocMe` links to private item `DontDocMe::f`
 // FIXME: for [private] we should also make sure the link was actually generated
 pub struct DocMe;
 struct DontDocMe;
+
+impl DontDocMe {
+    fn f() {}
+}