Attach (recommended) or Link to PDF file here:
[双引号不正常.pdf](https://github.com/mozilla/pdf.js/files/3533108/default.pdf)


Configuration:
- Web browser and its version:  IE11 , chrome 
- Operating system and its version:  win7
- PDF.js version:  master
- Is a browser extension: nothing 
teps to reproduce the problem:
1. viewer.html web  online preview


What is the expected behavior? (add screenshot)
Displayed in normal characters.

What went wrong? (add screenshot)
![20190823143813](https://user-images.githubusercontent.com/6269307/63571860-062e6600-c5b4-11e9-9fff-75d65cf6bade.png)

Not only the two characters I took screenshots, but also a lot of garbled Chinese punctuation. For example, the Chinese 《》 symbol. But these garbled characters only appear in some specific very old pdf files.

Link to a viewer (if hosted on a site other than mozilla.github.io/pdf.js or as Firefox/Chrome extension):nothing 

}
      if (lastCharIndex < code) {
        lastCharIndex = code;
      }
      const position = getUnicodeRangeFor(code);
      if (position < 32) {
        ulUnicodeRange1 |= 1 << position;
      } else if (position < 64) {
        ulUnicodeRange2 |= 1 << (position - 32);
      } else if (position < 96) {
        ulUnicodeRange3 |= 1 << (position - 64);
      } else if (position < 123) {
        ulUnicodeRange4 |= 1 << (position - 96);
      } else {
        throw new FormatError(
          "Unicode ranges Bits > 123 are reserved for internal usage"
        );
      }
    }
    if (lastCharIndex > 0xffff) {
      
      
      lastCharIndex = 0xffff;
    }
  } else {
    
    firstCharIndex = 0;
    lastCharIndex = 255;
  }
  const bbox = properties.bbox || [0, 0, 0, 0];