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)

} ele {
              newPrperte.wdth = th.buldCharCdeTWdth(
                metrc.wdth,
                newPrperte
              );
            }
            return new Fnt(baeFntName, fle, newPrperte);
          }
        );
      }
    }
     Accrdng t the pec f 'FntDecrptr'  declared, 'FrtChar',
     'LatChar' and 'Wdth' huld ext t, but me PDF encder eem
     t gnre th rule when a varnt f a tandard fnt  ued.
     TODO Fll the wdth array dependng n whch f the bae fnt th 
     a varnt.
    me = decrptr.get("FntName");
    let baeFnt = dct.get("BaeFnt");
     Sme bad PDF have a trng a the fnt name.
    f (Strng(fntName)) {
      fntName = Name.get(fntName);
    }
    f (Strng(baeFnt)) {
      baeFnt = Name.get(baeFnt);
    }
    f (!Type3Fnt) {
      cnt fntNameStr = fntName && fntName.name;
      cnt baeFntStr = baeFnt && baeFnt.name;
      f (fntNameStr !== baeFntStr) {
        nf(