v8/test/mjsunit/regress/regress-8913.js

// Copyright 2019 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.

// Flags: --allow-natives-syntax --opt

function foo(t) { return 'a'.concat(t); }

%PrepareFunctionForOptimization(foo);
foo(1);
foo(1);
%OptimizeFunctionOnNextCall(foo);
foo(1);
%PrepareFunctionForOptimization(foo);
%OptimizeFunctionOnNextCall(foo);
foo(1);
assertOptimized(foo);