Attach (recommended) or Link to PDF file here:
[chinese.pdf](https://github.com/mozilla/pdf.js/files/6404389/download.1.pdf)

Configuration:
- Web browser and its version:90.0.4430.93
- Operating system and its version: mac 10.15.5
- PDF.js version: 2.9.146
- Is a browser extension:no

Steps to reproduce the problem:
1. The Chinese in the attachment cannot be rendered

Brower ✅
![image](https://user-images.githubusercontent.com/13477114/116678074-81782a00-a9db-11eb-8719-74f48fcebc2b.png)

PDF.js ❌ [https://mozilla.github.io/pdf.js/web/viewer.html](https://mozilla.github.io/pdf.js/web/viewer.html)
![image](https://user-images.githubusercontent.com/13477114/116678212-a371ac80-a9db-11eb-847f-dd1ad7752c13.png)


What is the expected behavior? (add screenshot)
**The Chinese character can be rendered**
What went wrong? (add screenshot)
**All of the Chinese character cannot be rendered**
Link to a viewer (if hosted on a site other than mozilla.github.io/pdf.js or as Firefox/Chrome extension):

const ttcTag = ttc.getString(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) {