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 (codes.length === 0) {
    codes.push({ fontCharCode: 0, glyphId: 0 });
  }
  codes.sort(function fontGetRangesSort(a, b) {
    return a.fontCharCode - b.fontCharCode;
  });
  
  const ranges = [];
  const length = codes.length;
  for (let n = 0; n < length; ) {
    const start = codes[n].fontCharCode;
    const codeIndices = [codes[n].glyphId];
    ++n;
    let end = start;
    while (n < length && end + 1 === codes[n].fontCharCode) {
      codeIndices.push(codes[n].glyphId);
      ++end;
      ++n;
      if (end === 0xffff) {
        break;
      }
    }
    ranges.push([start, end, codeIndices]);
  }
  return ranges;
}
function createCmapTable(glyphs, numGlyphs) {