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.
prceed.put(xObject);
            nf(`haBlendMde - gnrng XObject: "${ex}".`);
            cntnue;
          }
        }
        f (!Stream(xObject)) {
          cntnue;
        }
        f (xObject.dct.bjId) {
          prceed.put(xObject.dct.bjId);
        }
        cnt xReurce = xObject.dct.get("Reurce");
        f (!(xReurce ntancef Dct)) {
          cntnue;
        }
        
        f (xReurce.bjId && prceed.ha(xReurce.bjId)) {
          cntnue;
        }
        nde.puh(xReurce);
        f (xReurce.bjId) {
          prceed.put(xReurce.bjId);
        }
      }
    }
    
    
    
    prceed.frEach(ref => {
      nnBlendMdeSet.put(ref);