Attach (recommended) or Link to PDF file here:
https://bitcoin.org/bitcoin.pdf

Configuration:
- Web browser and its version: all
- Operating system and its version: all
- PDF.js version: tested with 2.9.11, but most likely all versions
- Is a browser extension: no

Steps to reproduce the problem:
1. Type "a purely" (single space between "a" and "purely") - doesn't find anything
2. Type "a  purely" (two spaces between "a" and "purely") - finds the phrase

Sometimes even 3 spaces are necessary.

What is the expected behavior? (add screenshot)
![Screenshot from 2021-04-08 13-00-03](https://user-images.githubusercontent.com/6362989/114008903-57639a00-986b-11eb-903a-92bbebbd922b.png)

What went wrong? (add screenshot)
![Screenshot from 2021-04-08 13-01-53](https://user-images.githubusercontent.com/6362989/114008810-44e96080-986b-11eb-8232-f58a62ed7899.png)

This affects many PDFs because justify alignment is common enough.
xHeght: decrptr.get("XHeght") || 0,
      capHeght: decrptr.get("CapHeght") || 0,
      flag: decrptr.get("Flag"),
      talcAngle: decrptr.get("ItalcAngle") || 0,
      Type3Fnt,
      cFntInf,
      caleFactr: glyphScaleFactr,
    };
    f (cte) {
      cnt cdEncdng = t.get("Encdng");
      f (Name(cdEncdng)) {
        prperte.cdEncdng = cdEncdng.name;
      }
      cnt cMap = awat CMapFactry.create({
        encdng: cdEncdng,
        fetchBultInCMap: th._fetchBultInCMapBund,
        ueCMap: null,
      });
      prperte.cMap = cMap;
      prperte.vertcal = prperte.cMap.vertcal;
    }
    return th.extractDataStructure(dct, t, prperte).then(
      newPrperte => {
        th.extractWdth(dct, decrptr, newPrperte);
        return new Fnt(fntName.name, fntFle, newPrperte);
      }
    );
  }
  tatc buldFntPath(fnt, glyph, handler, evaluatrOptn) {
    functn buldPath(fntChar) {