Attach (recommended) or Link to PDF file here:
[test.pdf](https://github.com/mozilla/pdf.js/files/6715502/test.pdf)

Configuration:
- Web browser and its version: Google Chrome Version 91.0.4472.114 
- Operating system and its version: Windows 10 Enterprise
- PDF.js version: 
- Is a browser extension: yes

Steps to reproduce the problem:
1. download file
2. open file



What is the expected behavior? (add screenshot)
show symbol
![image](https://user-images.githubusercontent.com/50500976/123409847-55ca8800-d5b7-11eb-9e5b-c7f3b33c00e1.png)

What went wrong? (add screenshot)
Does not show symbol
![image](https://user-images.githubusercontent.com/50500976/123409707-274cad00-d5b7-11eb-9a64-b11dcf3cdc3f.png)
Link to a viewer (if hosted on a site other than mozilla.github.io/pdf.js or as Firefox/Chrome extension): Latest Version Chrome extension

}
    width = width || this.defaultWidth;
    return shadow(this, "spaceWidth", width);
  }
  /**
   * @private
   */
  _charToGlyph(charcode, isSpace = false) {
    let fontCharCode, width, operatorListId;
    let widthCode = charcode;
    if (this.cMap && this.cMap.contains(charcode)) {
      widthCode = this.cMap.lookup(charcode);
    }
    width = this.widths[widthCode];
    width = isNum(width) ? width : this.defaultWidth;
    const vmetric = this.vmetrics && this.vmetrics[widthCode];
    let unicode = this.toUnicode.get(charcode) || charcode;
    if (typeof unicode === "number") {
      unicode = String.fromCharCode(unicode);
    }
    let isInFont = this.toFontChar[charcode] !== undefined;
    
    
    fontCharCode = this.toFontChar[charcode] || charcode;
    if (this.missingFile) {
      const glyphName =
        this.differences[charcode] || this.defaultEncoding[charcode];
      if (
        (glyphName === ".notdef" || glyphName === "") &&
        this.type === "Type1"