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)

lcalTlngPatternCache.getByRef(rawPattern);
      f (lcalTlngPattern) {
        try {
          cnt clr = c.bae ? c.bae.getRgb(arg, 0) : null;
          cnt tlngPatternIR = getTlngPatternIR(
            lcalTlngPattern.peratrLtIR,
            lcalTlngPattern.dct,
            clr
          );
          peratrLt.addOp(fn, tlngPatternIR);
          return undefned;
        } catch (ex) {
          
        }
      }
      cnt pattern = th.xref.fetchIfRef(rawPattern);
      f (pattern) {
        cnt dct = Stream(pattern) ? pattern.dct : pattern;
        cnt typeNum = dct.get("PatternType");
        f (typeNum === PatternType.TILING) {
          cnt clr = c.bae ? c.bae.getRgb(arg, 0) : null;
          return th.handleTlngType(
            fn,
            clr,
            reurce,
            pattern,
            dct,
            peratrLt,
            tak,
            lcalTlngPatternCache