Attach (recommended) or Link to PDF file here:
[chinese.pdf](https://github.com/mozilla/pdf.js/files/6404389/download.1.pdf)

Configuration:
- Web browser and its version:90.0.4430.93
- Operating system and its version: mac 10.15.5
- PDF.js version: 2.9.146
- Is a browser extension:no

Steps to reproduce the problem:
1. The Chinese in the attachment cannot be rendered

Brower ✅
![image](https://user-images.githubusercontent.com/13477114/116678074-81782a00-a9db-11eb-8719-74f48fcebc2b.png)

PDF.js ❌ [https://mozilla.github.io/pdf.js/web/viewer.html](https://mozilla.github.io/pdf.js/web/viewer.html)
![image](https://user-images.githubusercontent.com/13477114/116678212-a371ac80-a9db-11eb-847f-dd1ad7752c13.png)


What is the expected behavior? (add screenshot)
**The Chinese character can be rendered**
What went wrong? (add screenshot)
**All of the Chinese character cannot be rendered**
Link to a viewer (if hosted on a site other than mozilla.github.io/pdf.js or as Firefox/Chrome extension):

return (b0 << 8) + b1;
}
function writeSignedInt16(bytes, index, value) {
  bytes[index + 1] = value;
  bytes[index] = value >>> 8;
}
function signedInt16(b0, b1) {
  const value = (b0 << 8) + b1;
  return value & (1 << 15) ? value - 0x10000 : value;
}
function int32(b0, b1, b2, b3) {
  return (b0 << 24) + (b1 << 16) + (b2 << 8) + b3;
}
function string16(value) {
  if (
    typeof PDFJSDev === "undefined" ||
    PDFJSDev.test("!PRODUCTION || TESTING")
  ) {
    assert(
      typeof value === "number" && Math.abs(value) < 2 ** 16,
      `string16: Unexpected input "${value}".`
    );
  }
  return String.fromCharCode((value >> 8) & 0xff, value & 0xff);
}
function safeString16(value) {