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

params[key] = new URL(source[key], window.location).href;
      continue;
    } else if (key === "range") {
      rangeTransport = source[key];
      continue;
    } else if (key === "worker") {
      worker = source[key];
      continue;
    } else if (key === "data" && !(source[key] instanceof Uint8Array)) {
      
      const pdfBytes = source[key];
      if (typeof pdfBytes === "string") {
        params[key] = stringToBytes(pdfBytes);
      } else if (
        typeof pdfBytes === "object" &&
        pdfBytes !== null &&
        !isNaN(pdfBytes.length)
      ) {
        params[key] = new Uint8Array(pdfBytes);
      } else if (isArrayBuffer(pdfBytes)) {
        params[key] = new Uint8Array(pdfBytes);
      } else {
        throw new Error(
          "Invalid PDF binary data: either typed array, " +
            "string or array-like object is expected in the " +
            "data property."
        );
      }
      continue;