comments

src/libsyntax/ast.rs

@@ -98,6 +98,7 @@ pub enum SyntaxContext_ {
     // in the "from" slot. In essence, they're all
     // pointers to a single "rename" event node.
     Rename (Ident,Name,SyntaxContext),
+    // actually, IllegalCtxt may not be necessary.
     IllegalCtxt
 }