Attach (recommended) or Link to PDF file here:
See pdf in https://github.com/mozilla/pdf.js/issues/3109

Configuration:
- Web browser and its version: Firefox nightly
- Operating system and its version: Windows 10
- PDF.js version: builtin viewer

Steps to reproduce the problem:
1. Look at outlines

What is the expected behavior? (add screenshot)
![image](https://user-images.githubusercontent.com/5641725/141514798-0e656865-1cbf-4fb8-a89b-530d36da23c9.png)

What went wrong? (add screenshot)
![image](https://user-images.githubusercontent.com/5641725/141514740-c95e0237-8bf4-4129-a4a5-cb2ea5a3f4df.png)

return str.replace(/([()\\\n\r])/g, match => {
    if (match === "\n") {
      return "\\n";
    } else if (match === "\r") {
      return "\\r";
    }
    return `\\${match}`;
  });
}
function isAscii(str) {
  return /^[\x00-\x7F]*$/.test(str);
}
function stringToUTF16BEString(str) {
  const buf = ["\xFE\xFF"];
  for (let i = 0, ii = str.length; i < ii; i++) {
    const char = str.charCodeAt(i);
    buf.push(
      String.fromCharCode((char >> 8) & 0xff),
      String.fromCharCode(char & 0xff)
    );
  }
  return buf.join("");
}
function stringToUTF8String(str) {