Attach (recommended) or Link to PDF file here:
https://bitcoin.org/bitcoin.pdf

Configuration:
- Web browser and its version: all
- Operating system and its version: all
- PDF.js version: tested with 2.9.11, but most likely all versions
- Is a browser extension: no

Steps to reproduce the problem:
1. Type "a purely" (single space between "a" and "purely") - doesn't find anything
2. Type "a  purely" (two spaces between "a" and "purely") - finds the phrase

Sometimes even 3 spaces are necessary.

What is the expected behavior? (add screenshot)
![Screenshot from 2021-04-08 13-00-03](https://user-images.githubusercontent.com/6362989/114008903-57639a00-986b-11eb-903a-92bbebbd922b.png)

What went wrong? (add screenshot)
![Screenshot from 2021-04-08 13-01-53](https://user-images.githubusercontent.com/6362989/114008810-44e96080-986b-11eb-8232-f58a62ed7899.png)

This affects many PDFs because justify alignment is common enough.
for (let j = 0, jj = points.length; j < jj; j++) {
      const t = Util.applyTransform(points[j], m);
      ts[j + 0] = c && (e.left - t[0]) / c;
      ts[j + 4] = s && (e.top - t[1]) / s;
      ts[j + 8] = c && (e.right - t[0]) / c;
      ts[j + 12] = s && (e.bottom - t[1]) / s;
      ts[j + 16] = s && (e.left - t[0]) / -s;
      ts[j + 20] = c && (e.top - t[1]) / c;
      ts[j + 24] = s && (e.right - t[0]) / -s;
      ts[j + 28] = c && (e.bottom - t[1]) / c;
      ts[j + 32] = c && (e.left - t[0]) / -c;
      ts[j + 36] = s && (e.top - t[1]) / -s;
      ts[j + 40] = c && (e.right - t[0]) / -c;
      ts[j + 44] = s && (e.bottom - t[1]) / -s;
      ts[j + 48] = s && (e.left - t[0]) / s;
      ts[j + 52] = c && (e.top - t[1]) / -c;
      ts[j + 56] = s && (e.right - t[0]) / s;
      ts[j + 60] = c && (e.bottom - t[1]) / -c;
    }
    
    
    const boxScale = 1 + Math.min(Math.abs(c), Math.abs(s));
    divProperties.paddingLeft = findPositiveMin(ts, 32, 16) / boxScale;
    divProperties.paddingTop = findPositiveMin(ts, 48, 16) / boxScale;
    divProperties.paddingRight = findPositiveMin(ts, 0, 16) / boxScale;
    divProperties.paddingBottom = findPositiveMin(ts, 16, 16) / boxScale;
    task._textDivProperties.set(div, divProperties);
  }
}
function expandBounds(width, height, boxes) {