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
}
            break;
          case 0x00030000:
            break;
          default:
            warn("Unknown/unsupported post table version " + version);
            valid = false;
            if (propertiesObj.defaultEncoding) {
              glyphNames = propertiesObj.defaultEncoding;
            }
            break;
        }
        propertiesObj.glyphNames = glyphNames;
        return valid;
      }
      function readNameTable(nameTable) {
        var start = (font.start ? font.start : 0) + nameTable.offset;
        font.pos = start;
        var names = [[], []];
        var length = nameTable.length,
          end = start + length;
        var format = font.getUint16();
        var FORMAT_0_HEADER_LENGTH = 6;
        if (format !== 0 || length < FORMAT_0_HEADER_LENGTH) {
          
          return names;
        }
        var numRecords = font.getUint16();
        var stringsStart = font.getUint16();
        var records = [];