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 (op >= 0x71 && op <= 0x75) {
            n = stack.pop();
            if (!isNaN(n)) {
              stackDelta = -n * 2;
            }
          }
          while (stackDelta < 0 && stack.length > 0) {
            stack.pop();
            stackDelta++;
          }
          while (stackDelta > 0) {
            stack.push(NaN); 
            stackDelta--;
          }
        }
      }
      ttContext.tooComplexToFollowFunctions = tooComplexToFollowFunctions;
      const content = [data];
      if (i > data.length) {
        content.push(new Uint8Array(i - data.length));
      }
      if (lastDeff > lastEndf) {
        warn("TT: complementing a missing function tail");
        
        
        content.push(new Uint8Array([0x22, 0x2d]));
      }
      foldTTTable(table, content);
    }
    function checkInvalidFunctions(ttContext, maxFunctionDefs) {