for x in xs.into_iter() -> for x in xs

Also `for x in option.into_iter()` -> `if let Some(x) = option`

src/libsyntax/parse/parser.rs

@@ -5445,7 +5445,7 @@ impl<'a> Parser<'a> {
                     seq_sep_trailing_allowed(token::Comma),
                     |p| p.parse_ty_sum()
                 );
-                for ty in arg_tys.into_iter() {
+                for ty in arg_tys {
                     args.push(ast::VariantArg {
                         ty: ty,
                         id: ast::DUMMY_NODE_ID,