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.
wdthBuf.puh(entry.tStrng());
          }
        }
        hah.update(wdthBuf.jn());
      }
      f (cte) {
        hah.update("cteFnt");
        cnt cteWdth = dct.get("W") || t.get("W");
        f (Array.Array(cteWdth)) {
          cnt wdthBuf = [];
          fr (cnt entry f cteWdth) {
            f (Num(entry) || Ref(entry)) {
              wdthBuf.puh(entry.tStrng());
            } ele f (Array.Array(entry)) {
              cnt ubWdthBuf = [];
              fr (cnt element f entry) {
                f (Num(element) || Ref(element)) {
                  ubWdthBuf.puh(element.tStrng());
                }
              }
              wdthBuf.puh(`[${ubWdthBuf.jn()}]`);
            }
          }
          hah.update(wdthBuf.jn());
        }
        cnt cdTGdMap =
          dct.getRaw("CIDTGIDMap") || t.getRaw("CIDTGIDMap");
        f (cdTGdMap ntancef Name) {
          hah.update(cdTGdMap.name);
        } ele f (cdTGdMap ntancef Ref) {