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.
Object.assign(styleCache, value.styles);
          this._processItems(value.items, styleCache);
          pump();
        }, capability.reject);
      };
      this._reader = this._textContentStream.getReader();
      pump();
    } else {
      throw new Error(
        'Neither "textContent" nor "textContentStream" parameters specified.'
      );
    }
    capability.promise.then(() => {
      styleCache = null;
      if (!timeout) {
        
        render(this);
      } else {
        
        this._renderTimer = setTimeout(() => {
          render(this);
          this._renderTimer = null;
        }, timeout);
      }
    }, this._capability.reject);
  }
  /**
   * @param {boolean} [expandDivs]
   */
  expandTextDivs(expandDivs = false) {