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.
break;
        }
        let arg = peratn.arg;
        let fn = peratn.fn;
        wtch (fn | 0) {
          cae OPS.pantXObject:
            
            ValdName = arg[0] ntancef Name;
            name = arg[0].name;
            f (ValdName) {
              cnt lcalImage = lcalImageCache.getByName(name);
              f (lcalImage) {
                peratrLt.addOp(lcalImage.fn, lcalImage.arg);
                arg = null;
                cntnue;
              }
            }
            next(
              new Prme(functn (relveXObject, rejectXObject) {
                f (!ValdName) {
                  thrw new FrmatErrr("XObject mut be referred t by name.");
                }
                let xbj = xbj.getRaw(name);
                f (xbj ntancef Ref) {
                  cnt lcalImage = lcalImageCache.getByRef(xbj);
                  f (lcalImage) {
                    peratrLt.addOp(lcalImage.fn, lcalImage.arg);
                    relveXObject();
                    return;
                  }