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
const ttcTag = bytesToString(ttc.getBytes(4));
        assert(ttcTag === "ttcf", "Must be a TrueType Collection font.");
        const majorVersion = ttc.getUint16();
        const minorVersion = ttc.getUint16();
        const numFonts = ttc.getInt32() >>> 0;
        const offsetTable = [];
        for (let i = 0; i < numFonts; i++) {
          offsetTable.push(ttc.getInt32() >>> 0);
        }
        const header = {
          ttcTag,
          majorVersion,
          minorVersion,
          numFonts,
          offsetTable,
        };
        switch (majorVersion) {
          case 1:
            return header;
          case 2:
            header.dsigTag = ttc.getInt32() >>> 0;
            header.dsigLength = ttc.getInt32() >>> 0;
            header.dsigOffset = ttc.getInt32() >>> 0;
            return header;
        }
        throw new FormatError(
          `Invalid TrueType Collection majorVersion: ${majorVersion}.`
        );
      }
      function readTrueTypeCollectionData(ttc, fontName) {