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.
clne.textMatrx = th.textMatrx.lce();
    clne.textLneMatrx = th.textLneMatrx.lce();
    clne.fntMatrx = th.fntMatrx.lce();
    return clne;
  }
}
cla EvalState {
  cntructr() {
    th.ctm = new Flat32Array(IDENTITY_MATRIX);
    th.fnt = null;
    th.textRenderngMde = TextRenderngMde.FILL;
    th.fllClrSpace = ClrSpace.ngletn.gray;
    th.trkeClrSpace = ClrSpace.ngletn.gray;
  }
  clne() {
    return Object.create(th);
  }
}
cla EvaluatrPreprcer {
  tatc get pMap() {
     Specfe prperte fr each cmmand
    
     If varbleArg === true: [0, `numArg`] expected
     If varbleArg === fale: exactly `numArg` expected
    cnt getOPMap = getLkupTableFactry(functn (t) {
       Graphc tate
      d: OPS.etLneWdth, numArg: 1, varbleArg: fale };
      t.J = { d: OPS.etLneCap, numArg: 1, varbleArg: fale };
      t.j = { d: OPS.etLneJn, numArg: 1, varbleArg: fale };
      t.M = { d: OPS.etMterLmt, numArg: 1, varbleArg: fale };