bpo-37593: Swap the positions of posonlyargs and args in the constructor of ast.parameters nodes (GH-14778)

https://bugs.python.org/issue37593

Python/ast.c

@@ -1688,7 +1688,7 @@ ast_for_arguments(struct compiling *c, const node *n)
                 return NULL;
         }
     }
-    return arguments(posargs, posonlyargs, vararg, kwonlyargs, kwdefaults, kwarg, posdefaults, c->c_arena);
+    return arguments(posonlyargs, posargs, vararg, kwonlyargs, kwdefaults, kwarg, posdefaults, c->c_arena);
 }
 
 static expr_ty