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

this._listeners.length = 0;
  }
}
/**
 * @typedef {Object} PDFWorkerParameters
 * @property {string} [name] - The name of the worker.
 * @property {Object} [port] - The `workerPort` object.
 * @property {number} [verbosity] - Controls the logging level; the
 *   constants from {@link VerbosityLevel} should be used.
 */
const PDFWorker = (function PDFWorkerClosure() {
  const pdfWorkerPorts = new WeakMap();
  let isWorkerDisabled = false;
  let fallbackWorkerSrc;
  let nextFakeWorkerId = 0;
  let fakeWorkerCapability;
  if (typeof PDFJSDev !== "undefined" && PDFJSDev.test("GENERIC")) {
    
    if (isNodeJS && typeof __non_webpack_require__ === "function") {
      
      isWorkerDisabled = true;
      if (typeof PDFJSDev !== "undefined" && PDFJSDev.test("LIB")) {
        fallbackWorkerSrc = "../pdf.worker.js";
      } else {
        fallbackWorkerSrc = "./pdf.worker.js";
      }
    } else if (typeof document === "object" && "currentScript" in document) {
      const pdfjsFilePath = document.currentScript?.src;
      if (pdfjsFilePath) {