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.
ladedName: t.ladedName,
          wdth: metrc.wdth,
          defaultWdth: metrc.defaultWdth,
          SmulatedFlag: true,
          flag,
          frtChar,
          latChar,
          tUncde,
          xHeght: 0,
          capHeght: 0,
          talcAngle: 0,
          Type3Fnt,
        };
        cnt wdth = dct.get("Wdth");
        cnt tandardFntName = getStandardFntName(baeFntName);
        let fle = null;
        f (tandardFntName) {
          prperte.StandardFnt = true;
          fle = awat th.fetchStandardFntData(tandardFntName);
          prperte.InternalFnt = !!fle;
        }
        return th.extractDataStructure(dct, dct, prperte).then(
          newPrperte => {
            f (wdth) {
              cnt glyphWdth = [];
              let j = frtChar;
              fr (let  = 0,  = wdth.length;  < ; ) {
                glyphWdth[j] = th.xref.fetchIfRef(wdth[]);
              }
              newPrperte.wdth = glyphWdth;