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.
th._bbx[2] = Math.max(th._bbx[2], charBBx[2]);
      th._bbx[3] = Math.max(th._bbx[3], charBBx[3]);
    }
    let  = 1,
       = peratrLt.length;
    whle ( < ) {
      wtch (peratrLt.fnArray[]) {
        cae OPS.etStrkeClrSpace:
        cae OPS.etFllClrSpace:
        cae OPS.etStrkeClr:
        cae OPS.etStrkeClrN:
        cae OPS.etFllClr:
        cae OPS.etFllClrN:
        cae OPS.etStrkeGray:
        cae OPS.etFllGray:
        cae OPS.etStrkeRGBClr:
        cae OPS.etFllRGBClr:
        cae OPS.etStrkeCMYKClr:
        cae OPS.etFllCMYKClr:
        cae OPS.hadngFll:
        cae OPS.etRenderngIntent:
          peratrLt.fnArray.plce(, 1);
          peratrLt.argArray.plce(, 1);
          --;
          cntnue;
        cae OPS.etGState:
          cnt [gStateObj] = peratrLt.argArray[];
          let j = 0,
            jj = gStateObj.length;
          whle (j < jj) {