Fix ICE calling method on auto trait

compiler/rustc_hir_typeck/src/method/suggest.rs

@@ -688,6 +688,16 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                                 let entry = spanned_predicates.entry(spans);
                                 entry.or_insert_with(|| (path, tr_self_ty, Vec::new())).2.push(p);
                             }
+                            Some(Node::Item(hir::Item {
+                                kind: hir::ItemKind::Trait(rustc_ast::ast::IsAuto::Yes, ..),
+                                span: item_span,
+                                ..
+                            })) => {
+                                tcx.sess.delay_span_bug(
+                                        *item_span,
+                                        "auto trait is invoked with no method error, but no error reported?",
+                                    );
+                            }
                             Some(_) => unreachable!(),
                             None => (),
                         }

src/test/ui/methods/issues/issue-105732.rs

@@ -0,0 +1,13 @@
+#![feature(auto_traits)]
+
+auto trait Foo {
+    fn g(&self); //~ ERROR auto traits cannot have associated items
+}
+
+trait Bar {
+    fn f(&self) {
+        self.g(); //~ ERROR the method `g` exists for reference `&Self`, but its trait bounds were not satisfied
+    }
+}
+
+fn main() {}

src/test/ui/methods/issues/issue-105732.stderr

@@ -0,0 +1,28 @@
+error[E0380]: auto traits cannot have associated items
+  --> $DIR/issue-105732.rs:4:8
+   |
+LL | auto trait Foo {
+   |            --- auto trait cannot have associated items
+LL |     fn g(&self);
+   |     ---^-------- help: remove these associated items
+
+error[E0599]: the method `g` exists for reference `&Self`, but its trait bounds were not satisfied
+  --> $DIR/issue-105732.rs:9:14
+   |
+LL |         self.g();
+   |              ^
+   |
+   = note: the following trait bounds were not satisfied:
+           `Self: Foo`
+           which is required by `&Self: Foo`
+           `&Self: Foo`
+   = help: items from traits can only be used if the type parameter is bounded by the trait
+help: the following trait defines an item `g`, perhaps you need to add a supertrait for it:
+   |
+LL | trait Bar: Foo {
+   |          +++++
+
+error: aborting due to 2 previous errors
+
+Some errors have detailed explanations: E0380, E0599.
+For more information about an error, try `rustc --explain E0380`.