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
for (j = 0; j < n; j++) {
                stack.push(data[i++]);
              }
            }
          } else if ((op & 0xf8) === 0xb8) {
            
            n = op - 0xb8 + 1;
            if (inFDEF || inELSE) {
              i += n * 2;
            } else {
              for (j = 0; j < n; j++) {
                b = data[i++];
                stack.push((b << 8) | data[i++]);
              }
            }
          } else if (op === 0x2b && !tooComplexToFollowFunctions) {
            
            if (!inFDEF && !inELSE) {
              
              funcId = stack[stack.length - 1];
              if (isNaN(funcId)) {
                info("TT: CALL empty stack (or invalid entry).");
              } else {
                ttContext.functionsUsed[funcId] = true;
                if (funcId in ttContext.functionsStackDeltas) {
                  const newStackLength =
                    stack.length + ttContext.functionsStackDeltas[funcId];
                  if (newStackLength < 0) {
                    warn("TT: CALL invalid functions stack delta.");
                    ttContext.hintsValid = false;