Attach (recommended) or Link to PDF file here:  [test.pdf](https://akmer.aikucun.com/a94a8fe5ccb19ba61c4c0873d391e987982fbbd3_1616477914120_83.pdf)


Configuration:
- Web browser and its version: chrome 87.0.4280.88
- Operating system and its version: windows10
- PDF.js version: 2.6.347
- Is a browser extension:

Steps to reproduce the problem:
1. just open 

What is the expected behavior? (add screenshot)

What went wrong? (add screenshot)
![image](https://user-images.githubusercontent.com/17724610/112087066-473f8f80-8bc8-11eb-8efb-56139ec42a9c.png)

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

stream.pos = trailers[i];
        const parser = new Parser({
          lexer: new Lexer(stream),
          xref: this,
          allowStreams: true,
          recoveryMode: true,
        });
        var obj = parser.getObj();
        if (!isCmd(obj, "trailer")) {
          continue;
        }
        
        const dict = parser.getObj();
        if (!isDict(dict)) {
          continue;
        }
        
        try {
          const rootDict = dict.get("Root");
          if (!(rootDict instanceof Dict)) {
            continue;
          }
          const pagesDict = rootDict.get("Pages");
          if (!(pagesDict instanceof Dict)) {
            continue;
          }
          const pagesCount = pagesDict.get("Count");
          if (!Number.isInteger(pagesCount)) {
            continue;
          }