cl-ast: Move loop expression into unary exprs (with lowest priority)

compiler/cl-repl/examples/yaml.rs

@@ -406,7 +406,6 @@ pub mod yamlify {
                 ExprKind::Empty => {}
                 ExprKind::Group(k) => k.yaml(y),
                 ExprKind::Tuple(k) => k.yaml(y),
-                ExprKind::Loop(k) => k.yaml(y),
                 ExprKind::While(k) => k.yaml(y),
                 ExprKind::If(k) => k.yaml(y),
                 ExprKind::For(k) => k.yaml(y),
@@ -537,12 +536,6 @@ pub mod yamlify {
             y.key("Group").yaml(expr);
         }
     }
-    impl Yamlify for Loop {
-        fn yaml(&self, y: &mut Yamler) {
-            let Self { body } = self;
-            y.key("Loop").yaml(body);
-        }
-    }
     impl Yamlify for While {
         fn yaml(&self, y: &mut Yamler) {
             let Self { cond, pass, fail } = self;