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):

info(
          "Attempting to fix invalid indexToLocFormat in head table: " +
            indexToLocFormat
        );
        
        
        
        
        
        
        
        
        
        const numGlyphsPlusOne = numGlyphs + 1;
        if (locaLength === numGlyphsPlusOne << 1) {
          
          data[50] = 0;
          data[51] = 0;
        } else if (locaLength === numGlyphsPlusOne << 2) {
          
          data[50] = 0;
          data[51] = 1;
        } else {
          throw new FormatError(
            "Could not fix indexToLocFormat: " + indexToLocFormat
          );
        }
      }
    }
    function sanitizeGlyphLocations(