Attach (recommended) or Link to PDF file here:
[test2-3.pdf](https://github.com/mozilla/pdf.js/files/7881930/test2-3.pdf)

Configuration:
- Web browser and its version: Chrome and Version 93.0.4577.63
- Operating system and its version: Ubuntu 20.04.1 LTS
- PDF.js version: v2.12.313
- Is a browser extension: No

What is the expected behavior? 
![Screenshot from 2022-01-17 18-21-02](https://user-images.githubusercontent.com/29357161/149772453-5906d92a-7cf5-458f-8315-695d78aa9674.png)


What went wrong? 
![Screenshot from 2022-01-17 18-20-24](https://user-images.githubusercontent.com/29357161/149772465-07dd71ef-5d41-42c9-8b13-466f8eee116a.png)


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

return program;
    }
    extractFontHeader(properties) {
      let token;
      while ((token = this.getToken()) !== null) {
        if (token !== "/") {
          continue;
        }
        token = this.getToken();
        switch (token) {
          case "FontMatrix":
            const matrix = this.readNumberArray();
            properties.fontMatrix = matrix;
            break;
          case "Encoding":
            const encodingArg = this.getToken();
            let encoding;
            if (!/^\d+$/.test(encodingArg)) {
              
              encoding = getEncoding(encodingArg);
            } else {
              encoding = [];
              const size = parseInt(encodingArg, 10) | 0;
              this.getToken(); 
              for (let j = 0; j < size; j++) {
                token = this.getToken();
                
                while (token !== "dup" && token !== "def") {
                  token = this.getToken();
                  if (token === null) {