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 (nameEntry === part) {
                fallbackData = {
                  name: part,
                  header: potentialHeader,
                  tables: potentialTables,
                };
              }
            }
          }
        }
      }
      if (fallbackData) {
        warn(
          `TrueType Collection does not contain "${fontName}" font, ` +
            `falling back to "${fallbackData.name}" font instead.`
        );
        return {
          header: fallbackData.header,
          tables: fallbackData.tables,
        };
      }
      throw new FormatError(
        `TrueType Collection does not contain "${fontName}" font.`
      );
    }
    /**
     * Read the appropriate subtable from the cmap according to 9.6.6.4 from
     * PDF spec
     */
    function readCmapTable(cmap, file, isSymbolicFont, hasEncoding) {