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 

proto = [[], []]; 
  }
  const strings = [
    proto[0][0] || "Original licence", 
    proto[0][1] || name, 
    proto[0][2] || "Unknown", 
    proto[0][3] || "uniqueID", 
    proto[0][4] || name, 
    proto[0][5] || "Version 0.11", 
    proto[0][6] || createPostscriptName(name), 
    proto[0][7] || "Unknown", 
    proto[0][8] || "Unknown", 
    proto[0][9] || "Unknown", 
  ];
  
  
  const stringsUnicode = [];
  let i, ii, j, jj, str;
  for (i = 0, ii = strings.length; i < ii; i++) {
    str = proto[1][i] || strings[i];
    const strBufUnicode = [];
    for (j = 0, jj = str.length; j < jj; j++) {
      strBufUnicode.push(string16(str.charCodeAt(j)));
    }
    stringsUnicode.push(strBufUnicode.join(""));
  }
  const names = [strings, stringsUnicode];
  const platforms = ["\x00\x01", "\x00\x03"];
  const encodings = ["\x00\x00", "\x00\x01"];
  const languages = ["\x00\x00", "\x04\x09"];