Attach (recommended) or Link to PDF file here:
https://www.nta.go.jp/taxes/tetsuzuki/shinsei/annai/joyaku/annai/pdf2/250.pdf

Configuration:
- Web browser and its version: Firefox 81.0a1
- Operating system and its version: Debian 5.6.7-1
- PDF.js version: latest in Firefox nightly
- Is a browser extension: No

Steps to reproduce the problem:
1. Open the pdf and paste the following text "本 店 又 は 主 た る 事 務 所 の 所 在 地" in "Full name" and in "Domicile and residence" textfields
2. Print or Save the pdf 

What is the expected behavior? (add screenshot)
![image](https://user-images.githubusercontent.com/5641725/91207547-30f05480-e709-11ea-9abd-2af5d970dc46.png)

What went wrong? (add screenshot)
![image](https://user-images.githubusercontent.com/5641725/91207663-69902e00-e709-11ea-8a1d-1ddd30cf0621.png)

Link to a viewer (if hosted on a site other than mozilla.github.io/pdf.js or as Firefox/Chrome extension):

if (size === 1) {
      return String.fromCharCode(a[0], a[1]);
    }
    if (size === 3) {
      return String.fromCharCode(a[0], a[1], a[2], a[3]);
    }
    return String.fromCharCode.apply(null, a.subarray(0, size + 1));
  }
  function addHex(a, b, size) {
    var c = 0;
    for (var i = size; i >= 0; i--) {
      c += a[i] + b[i];
      a[i] = c & 255;
      c >>= 8;
    }
  }
  function incHex(a, size) {
    var c = 1;
    for (var i = size; i >= 0 && c > 0; i--) {
      c += a[i];
      a[i] = c & 255;
      c >>= 8;
    }
  }
  var MAX_NUM_SIZE = 16;
  var MAX_ENCODED_NUM_SIZE = 19; 
  function BinaryCMapStream(data) {