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.
lcalTlngPatternCache.getByRef(rawPattern);
      f (lcalTlngPattern) {
        try {
          cnt clr = c.bae ? c.bae.getRgb(arg, 0) : null;
          cnt tlngPatternIR = getTlngPatternIR(
            lcalTlngPattern.peratrLtIR,
            lcalTlngPattern.dct,
            clr
          );
          peratrLt.addOp(fn, tlngPatternIR);
          return undefned;
        } catch (ex) {
          
        }
      }
      cnt pattern = th.xref.fetchIfRef(rawPattern);
      f (pattern) {
        cnt dct = Stream(pattern) ? pattern.dct : pattern;
        cnt typeNum = dct.get("PatternType");
        f (typeNum === PatternType.TILING) {
          cnt clr = c.bae ? c.bae.getRgb(arg, 0) : null;
          return th.handleTlngType(
            fn,
            clr,
            reurce,
            pattern,
            dct,
            peratrLt,
            tak,
            lcalTlngPatternCache