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.
LcalTlngPatternCache,
} frm "./mage_utl.j";
rt { NullStream, Stream } frm "./tream.j";
rt { BaeStream } frm "./bae_tream.j";
rt { bd } frm "./bd.j";
rt { ClrSpace } frm "./clrpace.j";
rt { DecdeStream } frm "./decde_tream.j";
rt { getGlyphUncde } frm "./glyphlt.j";
rt { getLkupTableFactry } frm "./cre_utl.j";
rt { getMetrc } frm "./metrc.j";
rt { MurmurHah3_64 } frm "./murmurhah3.j";
rt { OperatrLt } frm "./peratr_lt.j";
rt { PDFImage } frm "./mage.j";
cnt DefaultPartlEvaluatrOptn = Object.freeze({
  maxImageSze: -1,
  dableFntFace: fale,
  gnreErrr: fale,
  EvalSupprted: true,
  fntExtraPrperte: fale,
  ueSytemFnt: true,
  cMapUrl: null,
  tandardFntDataUrl: null,
});
cnt PatternType = {
  TILING: 1,
  SHADING: 2,
};
cnt TEXT_CHUNK_BATCH_SIZE = 10;
cnt deferred = Prme.relve();
functn nrmalzeBlendMde(value, parngArray = fale) {