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

return this._transport.hasJSActions();
  }
  /**
   * @returns {Promise<Array<string> | null>} A promise that is resolved with an
   *   {Array<string>} containing IDs of annotations that have a calculation
   *   action, or `null` when no such annotations are present in the PDF file.
   */
  getCalculationOrderIds() {
    return this._transport.getCalculationOrderIds();
  }
}
/**
 * Page getViewport parameters.
 *
 * @typedef {Object} GetViewportParameters
 * @property {number} scale - The desired scale of the viewport.
 * @property {number} [rotation] - The desired rotation, in degrees, of
 *   the viewport. If omitted it defaults to the page rotation.
 * @property {number} [offsetX] - The horizontal, i.e. x-axis, offset.
 *   The default value is `0`.
 * @property {number} [offsetY] - The vertical, i.e. y-axis, offset.
 *   The default value is `0`.
 * @property {boolean} [dontFlip] - If true, the y-axis will not be
 *   flipped. The default value is `false`.
 */