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):

this.buffer = data;
    this.pos = 0;
    this.end = data.length;
    this.tmpBuf = new Uint8Array(MAX_ENCODED_NUM_SIZE);
  }
  BinaryCMapStream.prototype = {
    readByte() {
      if (this.pos >= this.end) {
        return -1;
      }
      return this.buffer[this.pos++];
    },
    readNumber() {
      var n = 0;
      var last;
      do {
        var b = this.readByte();
        if (b < 0) {
          throw new FormatError("unexpected EOF in bcmap");
        }
        last = !(b & 0x80);
        n = (n << 7) | (b & 0x7f);
      } while (!last);
      return n;
    },
    readSigned() {
      var n = this.readNumber();
      return n & 1 ? ~(n >>> 1) : n >>> 1;
    },
    readHex(num, size) {