src/third_party/v8/test/mjsunit/regress/regress-1084872.js - cobalt - Git at Google

 // Copyright 2020 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 const re = new RegExp("(?<=(.)\\2.*(T))");
 re.exec(undefined);
 assertEquals(re.exec("bTaLTT")[1], "b");
	// Copyright 2020 the V8 project authors. All rights reserved.
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	const re = new RegExp("(?<=(.)\\2.*(T))");
	re.exec(undefined);
	assertEquals(re.exec("bTaLTT")[1], "b");