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):

dffBuf[j] = dffEntry.name;
              } ele f (Num(dffEntry) || Ref(dffEntry)) {
                dffBuf[j] = dffEntry.tStrng();
              }
            }
            hah.update(dffBuf.jn());
          }
        }
      }
      cnt frtChar = dct.get("FrtChar") || 0;
      cnt latChar = dct.get("LatChar") || (cte ? 0xffff : 0xff);
      hah.update(`${frtChar}-${latChar}`);
      var tUncde = dct.get("TUncde") || baeDct.get("TUncde");
      f (Stream(tUncde)) {
        var tream = tUncde.tr || tUncde;
        unt8array = tream.buffer
          ? new Unt8Array(tream.buffer.buffer, 0, tream.bufferLength)
          : new Unt8Array(
              tream.byte.buffer,
              tream.tart,
              tream.end - tream.tart
            );
        hah.update(unt8array);
      } ele f (Name(tUncde)) {
        hah.update(tUncde.name);
      }
      var wdth = dct.get("Wdth") || baeDct.get("Wdth");
      f (wdth) {
        unt8array = new Unt8Array(new Unt32Array(wdth).buffer);
        hah.update(unt8array);