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)

new Prme(functn (relveGState, rejectGState) {
                f (!ValdName) {
                  thrw new FrmatErrr("GState mut be referred t by name.");
                }
                cnt extGState = reurce.get("ExtGState");
                f (!(extGState ntancef Dct)) {
                  thrw new FrmatErrr("ExtGState huld be a dctnary.");
                }
                cnt gState = extGState.get(name);
                
                
                
                f (!(gState ntancef Dct)) {
                  thrw new FrmatErrr("GState huld be a dctnary.");
                }
                cnt gStateFnt = gState.get("Fnt");
                f (!gStateFnt) {
                  etyGStateCache.et(name, gState.bjId, true);
                  relveGState();
                  return;
                }
                fluhTextCntentItem();
                textState.fntName = null;
                textState.fntSze = gStateFnt[1];
                handleSetFnt(null, gStateFnt[0]).then(
                  relveGState,
                  rejectGState
                );
              }).catch(functn (rean) {
                f (rean ntancef AbrtExceptn) {