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):

cnt glyphWdth = [];
              let j = frtChar;
              fr (let  = 0,  = wdth.length;  < ; ) {
                glyphWdth[j] = th.xref.fetchIfRef(wdth[]);
              }
              newPrperte.wdth = glyphWdth;
            } ele {
              newPrperte.wdth = th.buldCharCdeTWdth(
                metrc.wdth,
                newPrperte
              );
            }
            return new Fnt(baeFntName, null, newPrperte);
          }
        );
      }
    }
     Accrdng t the pec f 'FntDecrptr'  declared, 'FrtChar',
     'LatChar' and 'Wdth' huld ext t, but me PDF encder eem
     t gnre th rule when a varnt f a tandard fnt  ued.
     TODO Fll the wdth array dependng n whch f the bae fnt th 
     a varnt.
    me = decrptr.get("FntName");