[accessors] handle `writable` changing during ArrayLengthSetter

test/mjsunit/array-length.js

 // Copyright 2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 114 matching lines @@
   var t = 239;
   t = a.length = 7;
   assertEquals(7, t);
 }
 
 (function () {
   "use strict";
   var frozen_object = Object.freeze({__proto__:[]});
   assertThrows(function () { frozen_object.length = 10 });
 })();
+
+(function sloppyReentrantDescriptorChange() {
+  var b = [];
+  b.length = {
+    valueOf() {
+      Object.defineProperty(b, "length", {writable: false});
+      return 1;
+    }
+  };
+  assertEquals(0, b.length);
+})();
+
+(function strictReentrantDescriptorChange() {
+  var b = [];
+  assertThrows(() => {
+    "use strict";
+    b.length = {
+      valueOf() {
+        Object.defineProperty(b, "length", {writable: false});
+        return 1;
+      }
+    };
+  }, TypeError);
+
+  b.length = { valueOf() { return 0; } };
+  assertEquals(0, b.length);
+})();