Attach (recommended) or Link to PDF file here:
[issue13075.pdf](https://github.com/mozilla/pdf.js/files/6117265/issue13075.pdf)

Configuration:
- Web browser and its version: Node.js 14.15.5
- Operating system and its version: Mac OS 11.2.1
- PDF.js version: master/2.7.570/2.6.347/1.10.100
- Is a browser extension: false

Steps to reproduce the problem:
1. const fileBuffer = fs.readFileSync('./pdf')
2. PDFJS.getDocument(fileBuffer)
3. fileBuffer.buffer has junk data at the start and at the end. Randomly, pdfjs can not read a buffer, whose buffer.buffer contains random memory junk data in fileBuffer.buffer

What is the expected behavior? pdfjs ignores a buffer.buffer and reads only buffer

What went wrong? (add screenshot)
I've catched that random error and wrote fileBuffer.buffer of the error buffer to a file named issue13075.pdf
I've recreated a buffer that has the wrong buffer.buffer (see line 6). Pdfjs fails to read that buffer (console.log('Fail')).
The Uint8Array of that buffer, pdfjs correctly reads (console.log('OK')).
![image](https://user-images.githubusercontent.com/8398353/110660366-59f1a780-8178-11eb-94c2-29be826c2118.png)


codesandbox:
https://codesandbox.io/s/pdfjs-loading-from-buffer-issue-9h4fd?file=/src/index.js

font.data = null;
              }
              this.commonObjs.resolve(id, font);
            });
          break;
        case "FontPath":
        case "Image":
          this.commonObjs.resolve(id, exportedData);
          break;
        default:
          throw new Error(`Got unknown common object type ${type}`);
      }
    });
    messageHandler.on("obj", data => {
      if (this.destroyed) {
        
        return undefined;
      }
      const [id, pageIndex, type, imageData] = data;
      const pageProxy = this.pageCache[pageIndex];
      if (pageProxy.objs.has(id)) {
        return undefined;
      }
      switch (type) {
        case "Image":
          pageProxy.objs.resolve(id, imageData);
          
          const MAX_IMAGE_SIZE_TO_STORE = 8000000;
          if (imageData?.data?.length > MAX_IMAGE_SIZE_TO_STORE) {