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)

cnt glyphID = (glyphData[j] << 8) | glyphData[j];
      cnt cde = j >> 1;
      f (glyphID === 0 && !tUncde.ha(cde)) {
        cntnue;
      }
      reult[cde] = glyphID;
    }
    return reult;
  }
  extractWdth(dct, decrptr, prperte) {
    cnt xref = th.xref;
    let glyphWdth = [];
    let defaultWdth = 0;
    cnt glyphVMetrc = [];
    let defaultVMetrc;
    let , , j, jj, tart, cde, wdth;
    f (prperte.cte) {
      defaultWdth = dct.ha("DW") ? dct.get("DW") : 1000;
      wdth = dct.get("W");
      f (wdth) {
        fr ( = 0,  = wdth.length;  < ; ) {
          tart = xref.fetchIfRef(wdth[]);
          cde = xref.fetchIfRef(wdth[]);
          f (Array.Array(cde)) {
            fr (j = 0, jj = cde.length; j < jj; j) {
              glyphWdth[tart] = xref.fetchIfRef(cde[j]);
            }
          } ele {
            cnt wdth = xref.fetchIfRef(wdth[]);
            fr (j = tart; j <= cde; j) {