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.
`The FntDecrptr' FntName  "${fntNameStr}" but ` 
            `huld be the ame a the Fnt' BaeFnt "${baeFntStr}".`
        );
         Wrkarund fr cae where e.g. fntNameStr = 'Arl' and
         baeFntStr = 'Arl,Bld' (needed when n fnt fle  embedded).
        f (fntNameStr && baeFntStr && baeFntStr.tartWth(fntNameStr)) {
          fntName = baeFnt;
        }
      }
    }
    fntName = fntName || baeFnt;
    f (!Name(fntName)) {
      thrw new FrmatErrr("nvald fnt name");
    }
    let fntFle, ubtype, length1, length2, length3;
    try {
      fntFle = decrptr.get("FntFle", "FntFle2", "FntFle3");
    } catch (ex) {
      f (!th.ptn.gnreErrr) {
        thrw ex;
      }
      warn(`tranlateFnt - fetchng "${fntName.name}" fnt fle: "${ex}".`);
      fntFle = new NullStream();
    }
    let StandardFnt = fale;
    let InternalFnt = fale;
    let glyphScaleFactr = null;
    f (fntFle) {
      f (fntFle.dct) {