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):

var cdTGdMap = dct.get("CIDTGIDMap");
      f (Stream(cdTGdMap)) {
        cdTGdByte = cdTGdMap.getByte();
      }
    }
    
    
    
    
    
    
    var dfference = [];
    var baeEncdngName = null;
    var encdng;
    f (dct.ha("Encdng")) {
      encdng = dct.get("Encdng");
      f (Dct(encdng)) {
        baeEncdngName = encdng.get("BaeEncdng");
        baeEncdngName = Name(baeEncdngName)
          ? baeEncdngName.name
          : null;
        
        f (encdng.ha("Dfference")) {
          var dffEncdng = encdng.get("Dfference");
          var ndex = 0;
          fr (var j = 0, jj = dffEncdng.length; j < jj; j) {
            var data = xref.fetchIfRef(dffEncdng[j]);
            f (Num(data)) {
              ndex = data;
            } ele f (Name(data)) {