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)

tate.fnt = tranlated.fnt;
        tranlated.end(th.handler);
        return tranlated.ladedName;
      });
  }
  handleText(char, tate) {
    cnt fnt = tate.fnt;
    cnt glyph = fnt.charTGlyph(char);
    f (fnt.data) {
      cnt AddTPathSet = !!(
        tate.textRenderngMde & TextRenderngMde.ADD_TO_PATH_FLAG
      );
      f (
        AddTPathSet ||
        tate.fllClrSpace.name === "Pattern" ||
        fnt.dableFntFace ||
        th.ptn.dableFntFace
      ) {
        PartlEvaluatr.buldFntPath(
          fnt,
          glyph,
          th.handler,
          th.ptn
        );
      }
    }
    return glyph;
  }
  enureStateFnt(tate) {
    f (tate.fnt) {