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 

case "TrueType":
        case "CIDFontType2":
          this.mimetype = "font/opentype";
          
          
          data = this.checkAndRepair(name, file, properties);
          if (this.isOpenType) {
            adjustWidths(properties);
            type = "OpenType";
          }
          break;
        default:
          throw new FormatError(`Font ${type} is not supported`);
      }
    } catch (e) {
      warn(e);
      this.fallbackToSystemFont(properties);
      return;
    }
    amendFallbackToUnicode(properties);
    this.data = data;
    this.fontType = getFontType(type, subtype, properties.isStandardFont);
    
    this.fontMatrix = properties.fontMatrix;
    this.widths = properties.widths;
    this.defaultWidth = properties.defaultWidth;
    this.toUnicode = properties.toUnicode;
    this.seacMap = properties.seacMap;
  }
  get renderer() {