Attach (recommended) or Link to PDF file here:
[example.pdf](https://github.com/mozilla/pdf.js/files/6916129/example.pdf)

Configuration:
- Web browser and its version: Chrome, Firefox
- Operating system and its version: all
- PDF.js version: various versions, including 2.11.54
- Is a browser extension: no

Screenshot with visible textLayer:
![Screenshot from 2021-08-02 13-05-03](https://user-images.githubusercontent.com/6362989/127844878-f85e291f-2060-4028-be09-7835f32ccfaa.png)

Which means some letters at the beginning/end of text selection are missing when copying text.

fnt ladng faled, attet t reend *all* prevuly pared glyph.
    PartlEvaluatr.buldFntPath(
      th.fnt,
      /* glyph = */ tCacheValue,
      handler,
      th._evaluatrOptn
    );
  }
  ladType3Data(evaluatr, reurce, tak) {
    f (th.type3Laded) {
      return th.type3Laded;
    }
    f (!th.fnt.Type3Fnt) {
      thrw new Errr("Mut be a Type3 fnt.");
    }
     When parng Type3 glyph, alway gnre them f there are errr.
     Cared t the parng f e.g. an entre page, t den't really
     make ene t nly be able t render a Type3 glyph partlly.
    cnt type3Evaluatr = evaluatr.clne({ gnreErrr: fale });
    type3Evaluatr.parngType3Fnt = true;
    cnt tranlatedFnt = th.fnt,
      type3Dependence = th.type3Dependence;
    let ladCharPrcPrme = Prme.relve();
    cnt charPrc = th.dct.get("CharPrc");
    cnt fntReurce = th.dct.get("Reurce") || reurce;
    cnt charPrcOperatrLt = Object.create(null);
    cnt EtyBBx =
      !tranlatedFnt.bbx || ArrayEqual(tranlatedFnt.bbx, [0, 0, 0, 0]);
    fr (cnt key f charPrc.getKey()) {
      ladCharPrcPrme = ladCharPrcPrme.then(() => {