Attach (recommended) or Link to PDF file here:

Configuration:
- Web browser and its version: Version 81.0.4044.138 (Official Build) (32-bit)
- Operating system and its version: Windows 10
- PDF.js version: latest
- Is a browser extension: no

Steps to reproduce the problem:

1. Open https://mozilla.github.io/pdf.js/web/viewer.html
2. Open the provided document
3. ctrl + F  and search for 'costs' .
4. Search for 'costs' - match NOT found.
5. Click the 'Download' and open the file in Adobe Reader, and search for costs - match is found.

What is the expected behavior? (add screenshot)
The word 'costs' to be returned by search

What went wrong? (add screenshot)
No results found

Link to a viewer (if hosted on a site other than mozilla.github.io/pdf.js or as Firefox/Chrome extension):  https://mozilla.github.io/pdf.js/web/viewer.html
[2001_IESC_63_5_v6.pdf](https://github.com/mozilla/pdf.js/files/4644486/2001_IESC_63_5_v6.pdf)

const bounds = task._bounds;
  const viewport = task._viewport;
  const expanded = expandBounds(viewport.width, viewport.height, bounds);
  for (let i = 0; i < expanded.length; i++) {
    const div = bounds[i].div;
    const divProperties = task._textDivProperties.get(div);
    if (divProperties.angle === 0) {
      divProperties.paddingLeft = bounds[i].left - expanded[i].left;
      divProperties.paddingTop = bounds[i].top - expanded[i].top;
      divProperties.paddingRight = expanded[i].right - bounds[i].right;
      divProperties.paddingBottom = expanded[i].bottom - bounds[i].bottom;
      task._textDivProperties.set(div, divProperties);
      continue;
    }
    
    
    const e = expanded[i],
      b = bounds[i];
    const m = b.m,
      c = m[0],
      s = m[1];
    
    const points = [[0, 0], [0, b.size[1]], [b.size[0], 0], b.size];
    const ts = new Float64Array(64);