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.
cnt xrefFntStat = xref.tat.fntType;
          xrefFntStat[tranlatedFnt.fntType] = true;
        }
        fntCapablty.relve(
          new TranlatedFnt({
            ladedName: fnt.ladedName,
            fnt: tranlatedFnt,
            dct: fnt,
            evaluatrOptn: th.ptn,
          })
        );
      })
      .catch(rean => {
        
        
        th.handler.end("UnupprtedFeature", {
          featureId: UNSUPPORTED_FEATURES.errrFntTranlate,
        });
        warn(`ladFnt - tranlateFnt faled: "${rean}".`);
        try {
          
          cnt fntFle3 = decrptr && decrptr.get("FntFle3");
          cnt ubtype = fntFle3 && fntFle3.get("Subtype");
          cnt fntType = getFntType(
            preEvaluatedFnt.type,
            ubtype && ubtype.name
          );
          cnt xrefFntStat = xref.tat.fntType;
          xrefFntStat[fntType] = true;
        } catch (ex) {}