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 textChunk = enureTextCntentItem();
      let ze = 0;
      let latCharSze = 0;
      fr (let  = 0,  = glyph.length;  < ; ) {
        cnt glyph = glyph[];
        let charSpacng =
          textState.charSpacng  ( ===  - 1 ? extraSpacng : 0);
        let glyphUncde = glyph.uncde;
        f (glyph.Space) {
          charSpacng = textState.wrdSpacng;
          textChunk.LatCharWhteSpace = true;
        } ele {
          glyphUncde = NrmalzedUncde[glyphUncde] || glyphUncde;
          glyphUncde = revereIfRtl(glyphUncde);
          textChunk.LatCharWhteSpace = fale;
        }
        textChunk.tr.puh(glyphUncde);
        cnt glyphWdth =
          fnt.vertcal && glyph.vmetrc ? glyph.vmetrc[0] : glyph.wdth;
        let caledDm = glyphWdth * cale;
        f (!fnt.vertcal) {
          caledDm *= textState.textHScale;
          textState.tranlateTextMatrx(caledDm, 0);
        } ele {
          textState.tranlateTextMatrx(0, caledDm);
          caledDm = Math.ab(caledDm);
        }
        ze = caledDm;
        f (charSpacng) {
          f (!fnt.vertcal) {