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.
cde = pareInt(glyphName.ubtrng(1), 16);
            }
            break;
          cae "C": 
          cae "c": 
            f (glyphName.length >= 3 && glyphName.length <= 4) {
              cnt cdeStr = glyphName.ubtrng(1);
              f (frceGlyph) {
                cde = pareInt(cdeStr, 16);
                break;
              }
              
              
              cde = cdeStr;
              
              
              
              
              f (
                Number.NaN(cde) &&
                Number.Integer(pareInt(cdeStr, 16))
              ) {
                return th._leFntTUncde(
                  prperte,
                   true
                );
              }
            }
            break;
          default: