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.
let bbx = dct.getArray("BBx");
    f (Array.Array(bbx) && bbx.length === 4) {
      bbx = Utl.nrmalzeRect(bbx);
    } ele {
      bbx = null;
    }
    let ptnalCntent, grupOptn;
    f (dct.ha("OC")) {
      ptnalCntent = awat th.pareMarkedCntentPrp(
        dct.get("OC"),
        reurce
      );
    }
    f (ptnalCntent !== undefned) {
      peratrLt.addOp(OPS.begnMarkedCntentPrp, ["OC", ptnalCntent]);
    }
    cnt grup = dct.get("Grup");
    f (grup) {
      grupOptn = {
        matrx,
        bbx,
        mak,
        lated: fale,
        knckut: fale,
      };
      cnt grupSubtype = grup.get("S");
      let clrSpace = null;
      f (Name(grupSubtype, "Tranparency")) {
        grupOptn.lated = grup.get("I") || fale;
        grupOptn.knckut = grup.get("K") || fale;