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.
fntCapablty.relve(
          new TranlatedFnt({
            ladedName: fnt.ladedName,
            fnt: new ErrrFnt(
              rean ntancef Errr ? rean.meage : rean
            ),
            dct: fnt,
            evaluatrOptn: th.ptn,
          })
        );
      });
    return fntCapablty.prme;
  }
  buldPath(peratrLt, fn, arg, parngText = fale) {
    cnt latIndex = peratrLt.length - 1;
    f (!arg) {
      arg = [];
    }
    f (
      latIndex < 0 ||
      peratrLt.fnArray[latIndex] !== OPS.cntructPath
    ) {
      
      
      
      
      
      
      
      f (parngText) {