rustdoc: stop treating everything in a trait item as a method

This was added in 0b9b4b7 to fix the
spacing on trait pages, but stopped being needed because
791f04e stopped styling method-toggle.
By only putting the method-toggle class on actual methods, the JS setting
does the right thing.

src/librustdoc/formats/item_type.rs

@@ -177,6 +177,9 @@ impl ItemType {
             ItemType::TraitAlias => "traitalias",
         }
     }
+    pub(crate) fn is_method(&self) -> bool {
+        matches!(*self, ItemType::Method | ItemType::TyMethod)
+    }
 }
 
 impl fmt::Display for ItemType {

src/librustdoc/html/render/mod.rs

@@ -1512,8 +1512,7 @@ fn render_impl(
 
         let toggled = !doc_buffer.is_empty();
         if toggled {
-            let method_toggle_class =
-                if item_type == ItemType::Method { " method-toggle" } else { "" };
+            let method_toggle_class = if item_type.is_method() { " method-toggle" } else { "" };
             write!(w, "<details class=\"rustdoc-toggle{}\" open><summary>", method_toggle_class);
         }
         match &*item.kind {

src/librustdoc/html/render/print_item.rs

@@ -732,7 +732,8 @@ fn item_trait(w: &mut Buffer, cx: &mut Context<'_>, it: &clean::Item, t: &clean:
         document(&mut content, cx, m, Some(t), HeadingOffset::H5);
         let toggled = !content.is_empty();
         if toggled {
-            write!(w, "<details class=\"rustdoc-toggle method-toggle\" open><summary>");
+            let method_toggle_class = if item_type.is_method() { " method-toggle" } else { "" };
+            write!(w, "<details class=\"rustdoc-toggle{method_toggle_class}\" open><summary>");
         }
         write!(w, "<section id=\"{}\" class=\"method has-srclink\">", id);
         render_rightside(w, cx, m, t, RenderMode::Normal);

src/test/rustdoc/toggle-trait-fn.rs

@@ -4,13 +4,20 @@
 // summary. Trait methods with no documentation should not be wrapped.
 //
 // @has foo/trait.Foo.html
+// @has - '//details[@class="rustdoc-toggle"]//summary//h4[@class="code-header"]' 'type Item'
+// @!has - '//details[@class="rustdoc-toggle"]//summary//h4[@class="code-header"]' 'type Item2'
 // @has -  '//details[@class="rustdoc-toggle method-toggle"]//summary//h4[@class="code-header"]' 'is_documented()'
 // @!has - '//details[@class="rustdoc-toggle method-toggle"]//summary//h4[@class="code-header"]' 'not_documented()'
 // @has -  '//details[@class="rustdoc-toggle method-toggle"]//*[@class="docblock"]' 'is_documented is documented'
 // @has -  '//details[@class="rustdoc-toggle method-toggle"]//summary//h4[@class="code-header"]' 'is_documented_optional()'
 // @!has - '//details[@class="rustdoc-toggle method-toggle"]//summary//h4[@class="code-header"]' 'not_documented_optional()'
 // @has -  '//details[@class="rustdoc-toggle method-toggle"]//*[@class="docblock"]' 'is_documented_optional is documented'
 pub trait Foo {
+    /// is documented
+    type Item;
+
+    type Item2;
+
     fn not_documented();
 
     /// is_documented is documented