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 

numGlyphs,
      dupFirstEntry
    ) {
      if (!header) {
        if (metrics) {
          metrics.data = null;
        }
        return;
      }
      file.pos = (file.start ? file.start : 0) + header.offset;
      file.pos += 4; 
      file.pos += 2; 
      file.pos += 2; 
      file.pos += 2; 
      file.pos += 2; 
      file.pos += 2; 
      file.pos += 2; 
      file.pos += 2; 
      file.pos += 2; 
      file.pos += 2; 
      const caretOffset = file.getUint16();
      file.pos += 8; 
      file.pos += 2; 
      let numOfMetrics = file.getUint16();
      if (caretOffset !== 0) {
        const macStyle = int16(headTable.data[44], headTable.data[45]);
        if (!(macStyle & 2)) {
          
          header.data[22] = 0;
          header.data[23] = 0;