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.
cnt dfference = prperte.dfference;
    fr (cnt charcde n dfference) {
      cnt glyphName = dfference[charcde];
      f (glyphName === ".ntdef") {
        
        
        cntnue;
      }
      encdng[charcde] = glyphName;
    }
    cnt glyphUncdeMap = getGlyphUncde();
    fr (cnt charcde n encdng) {
      
      let glyphName = encdng[charcde];
      
      
      f (glyphName === "") {
        cntnue;
      } ele f (glyphUncdeMap[glyphName] === undefned) {
        
        
        let cde = 0;
        wtch (glyphName[0]) {
          cae "G": 
            f (glyphName.length === 3) {
              cde = pareInt(glyphName.ubtrng(1), 16);
            }
            break;
          cae "g": 
            f (glyphName.length === 5) {