Attach (recommended) or Link to PDF file here:
[test.pdf](https://github.com/mozilla/pdf.js/files/6270827/test.pdf)
Configuration:
- Web browser and its version:chrome 89
- Operating system and its version:win10
- PDF.js version: 2.4/2.7/2.8 no working
- Is a browser extension: no 

What is the expected behavior? (add screenshot)
![image](https://user-images.githubusercontent.com/18545199/113852392-1ae26080-97cf-11eb-9dc9-0cecf52d267b.png)

What went wrong? (add screenshot)
![1617791294(1)](https://user-images.githubusercontent.com/18545199/113852355-10c06200-97cf-11eb-8672-598750f1093a.jpg)


console this log : **FormatError: TrueType Collection does not contain "DCWGQU+CambriaMath" font** 

any solution?thanks
return this.cff.charStrings.count;
    },
    getCharset: function CFFFont_getCharset() {
      return this.cff.charset.charset;
    },
    getGlyphMapping: function CFFFont_getGlyphMapping() {
      var cff = this.cff;
      var properties = this.properties;
      var charsets = cff.charset.charset;
      var charCodeToGlyphId;
      var glyphId;
      if (properties.composite) {
        charCodeToGlyphId = Object.create(null);
        let charCode;
        if (cff.isCIDFont) {
          
          
          for (glyphId = 0; glyphId < charsets.length; glyphId++) {
            var cid = charsets[glyphId];
            charCode = properties.cMap.charCodeOf(cid);
            charCodeToGlyphId[charCode] = glyphId;
          }