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):

"\x01\xDF" + 
    "\x00\x31" + 
    "\x01\x02" + 
    "\x00\x00" + 
    "\x00\x00\x06" +
    String.fromCharCode(properties.fixedPitch ? 0x09 : 0x00) +
    "\x00\x00\x00\x00\x00\x00" + 
    string32(ulUnicodeRange1) + 
    string32(ulUnicodeRange2) + 
    string32(ulUnicodeRange3) + 
    string32(ulUnicodeRange4) + 
    "\x2A\x32\x31\x2A" + 
    string16(properties.italicAngle ? 1 : 0) + 
    string16(firstCharIndex || properties.firstChar) + 
    string16(lastCharIndex || properties.lastChar) + 
    string16(typoAscent) + 
    string16(typoDescent) + 
    "\x00\x64" + 
    string16(winAscent) + 
    string16(winDescent) + 
    "\x00\x00\x00\x00" + 
    "\x00\x00\x00\x00" + 
    string16(properties.xHeight) + 
    string16(properties.capHeight) + 
    string16(0) + 
    string16(firstCharIndex || properties.firstChar) + 
    "\x00\x03"
  ); 
}
function createPostTable(properties) {