Disallow tail calls from async functions and generators

test/mjsunit/regress/regress-639270.js

Index: test/mjsunit/regress/regress-639270.js
diff --git a/test/mjsunit/regress/regress-crbug-621816.js b/test/mjsunit/regress/regress-639270.js
similarity index 57%
copy from test/mjsunit/regress/regress-crbug-621816.js
copy to test/mjsunit/regress/regress-639270.js
index ca7f5ac6df314f81e4c73f9417d1a6f3240540fc..0924650de71296bb205d6727de386a361d08db55 100644
--- a/test/mjsunit/regress/regress-crbug-621816.js
+++ b/test/mjsunit/regress/regress-639270.js
@@ -2,17 +2,13 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --allow-natives-syntax --turbo
+// Flags: --allow-natives-syntax --es-staging --ignition-staging --turbo
 
-function f() {
-  var o = {};
-  o.a = 1;
-}
-function g() {
-  var o = { ['a']: function(){} };
-  f();
-}
-f();
-f();
+"use strict";
+
+var g = (async () => { return JSON.stringify() });
+
+g();
+g();
 %OptimizeFunctionOnNextCall(g);
 g();