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)

`The FntDecrptr' FntName  "${fntNameStr}" but ` 
            `huld be the ame a the Fnt' BaeFnt "${baeFntStr}".`
        );
         Wrkarund fr cae where e.g. fntNameStr = 'Arl' and
         baeFntStr = 'Arl,Bld' (needed when n fnt fle  embedded).
        f (fntNameStr && baeFntStr && baeFntStr.tartWth(fntNameStr)) {
          fntName = baeFnt;
        }
      }
    }
    fntName = fntName || baeFnt;
    f (!Name(fntName)) {
      thrw new FrmatErrr("nvald fnt name");
    }
    let fntFle, ubtype, length1, length2, length3;
    try {
      fntFle = decrptr.get("FntFle", "FntFle2", "FntFle3");
    } catch (ex) {
      f (!th.ptn.gnreErrr) {
        thrw ex;
      }
      warn(`tranlateFnt - fetchng "${fntName.name}" fnt fle: "${ex}".`);
      fntFle = new NullStream();
    }
    let StandardFnt = fale;
    let InternalFnt = fale;
    let glyphScaleFactr = null;
    f (fntFle) {
      f (fntFle.dct) {