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 

return (b0 << 8) + b1;
}
function writeSignedInt16(bytes, index, value) {
  bytes[index + 1] = value;
  bytes[index] = value >>> 8;
}
function signedInt16(b0, b1) {
  const value = (b0 << 8) + b1;
  return value & (1 << 15) ? value - 0x10000 : value;
}
function int32(b0, b1, b2, b3) {
  return (b0 << 24) + (b1 << 16) + (b2 << 8) + b3;
}
function string16(value) {
  if (
    typeof PDFJSDev === "undefined" ||
    PDFJSDev.test("!PRODUCTION || TESTING")
  ) {
    assert(
      typeof value === "number" && Math.abs(value) < 2 ** 16,
      `string16: Unexpected input "${value}".`
    );
  }
  return String.fromCharCode((value >> 8) & 0xff, value & 0xff);
}
function safeString16(value) {