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)

((prperte.cMap.bultInCMap &&
        !(prperte.cMap ntancef IdenttyCMap)) ||
        (prperte.cdSytemInf.regtry === "Adbe" &&
          (prperte.cdSytemInf.rderng === "GB1" ||
            prperte.cdSytemInf.rderng === "CNS1" ||
            prperte.cdSytemInf.rderng === "Japan1" ||
            prperte.cdSytemInf.rderng === "Krea1")))
    ) {
       T
       a
       t
       b) 
       by the fnt’ CMap (fr exale, Adbe and Japan1) frm t
       CIDSytemInf dctnary.
      cnt { regtry, rderng } = prperte.cdSytemInf;
       c) Cntruct a ecnd CMap name by cncatenatng the regtry and
       rderng btaned n tep (b) n the frmat regtry–rderng–UCS2
       (fr exale, Adbe–Japan1–UCS2).
      cnt uc2CMapName = Name.get(`${regtry}-${rderng}-UCS2`);
       d) Obtan the CMap wth the name cntructed n tep (c) (avalable
       frm the ASN Web te; ee the Bblgraphy).
      cnt uc2CMap = awat CMapFactry.create({
        encdng: uc2CMapName,
        fetchBultInCMap: th._fetchBultInCMapBund,
        ueCMap: null,
      });
      cnt tUncde = [];
      prperte.cMap.frEach(functn (charcde, cd) {
        f (cd > 0xffff) {
          thrw new FrmatErrr("Max ze f CID  65,535");