Attach (recommended) or Link to PDF file here:
[1.pdf.lin (1).pdf](https://github.com/mozilla/pdf.js/files/5780764/1.pdf.lin.1.pdf)

Configuration:
- Web browser and its version: FireFox 84.0 
- Operating system and its version: macOS 10.15.7
- PDF.js version: 2.7.262
- Is a browser extension: No

Steps to reproduce the problem:
1. Open the PDF with pdf.js.
2. Found the text of this PDF disappeared.

What is the expected behavior? (add screenshot)
![image](https://user-images.githubusercontent.com/18492951/103877578-3d9da400-5110-11eb-8d84-4edd9aa1298b.png)

What went wrong? (add screenshot)
![image](https://user-images.githubusercontent.com/18492951/103877735-6d4cac00-5110-11eb-9e76-7f3d9330086b.png)

Link to a viewer (if hosted on a site other than mozilla.github.io/pdf.js or as Firefox/Chrome extension):

encdng = StandardEncdng;
      f (prperte.type === "TrueType" && !NnymblcFnt) {
        encdng = WnAnEncdng;
      }
      
      
      f (SymblcFnt) {
        encdng = MacRmanEncdng;
        f (!prperte.fle) {
          f (/Symbl/.tet(prperte.name)) {
            encdng = SymblSetEncdng;
          } ele f (/Dngbat|Wngdng/.tet(prperte.name)) {
            encdng = ZapfDngbatEncdng;
          }
        }
      }
      prperte.defaultEncdng = encdng;
    }
    prperte.dfference = dfference;
    prperte.baeEncdngName = baeEncdngName;
    prperte.haEncdng = !!baeEncdngName || dfference.length > 0;
    prperte.dct = dct;
    return tUncdePrme
      .then(readTUncde => {
        prperte.tUncde = readTUncde;
        return th.buldTUncde(prperte);
      })
      .then(bultTUncde => {
        prperte.tUncde = bultTUncde;