rustdoc: show attributes on enum variants

mostly for #[non_exhaustive]

Author: lolbinarycat

src/librustdoc/html/render/print_item.rs

@@ -1702,6 +1702,7 @@ fn render_enum_fields(
                 if v.is_stripped() {
                     continue;
                 }
+                write!(w, "{}", render_attributes_in_pre(v, TAB, cx))?;
                 w.write_str(TAB)?;
                 match v.kind {
                     clean::VariantItem(ref var) => match var.kind {

tests/rustdoc/enum/enum-variant-non_exhaustive.rs

@@ -0,0 +1,17 @@
+// regression test for https://github.com/rust-lang/rust/issues/142599
+
+#![crate_name = "foo"]
+
+//@ snapshot type-code 'foo/enum.Type.html' '//pre[@class="rust item-decl"]/code'
+pub enum Type {
+    #[non_exhaustive]
+    // attribute that should not be shown
+    #[warn(unsafe_code)]
+    Variant,
+}
+
+// we would love to use the `following-sibling::` axis
+// (along with an `h2[@id="aliased-type"]` query),
+// but unfortunatly python doesn't implement that.
+//@ snapshot type-alias-code 'foo/type.TypeAlias.html' '//pre[@class="rust item-decl"][1]/code'
+pub type TypeAlias = Type;

tests/rustdoc/enum/enum-variant-non_exhaustive.type-alias-code.html

@@ -0,0 +1 @@
+<code>pub type TypeAlias = <a class="enum" href="enum.Type.html" title="enum foo::Type">Type</a>;</code>

tests/rustdoc/enum/enum-variant-non_exhaustive.type-code.html

@@ -0,0 +1,4 @@
+<code>pub enum Type {
+    #[non_exhaustive]
+    Variant,
+}</code>