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.
);
      const pdfDoc = await loadingTask.promise;
      const docActions = await pdfDoc.getJSActions();
      const page1 = await pdfDoc.getPage(1);
      const page1Actions = await page1.getJSActions();
      const page3 = await pdfDoc.getPage(3);
      const page3Actions = await page3.getJSActions();
      expect(docActions).toEqual({
        DidPrint: [`this.getField("Text2").value = "DidPrint";`],
        DidSave: [`this.getField("Text2").value = "DidSave";`],
        WillClose: [`this.getField("Text1").value = "WillClose";`],
        WillPrint: [`this.getField("Text1").value = "WillPrint";`],
        WillSave: [`this.getField("Text1").value = "WillSave";`],
      });
      expect(page1Actions).toEqual({
        PageOpen: [`this.getField("Text1").value = "PageOpen 1";`],
        PageClose: [`this.getField("Text2").value = "PageClose 1";`],
      });
      expect(page3Actions).toEqual({
        PageOpen: [`this.getField("Text5").value = "PageOpen 3";`],
        PageClose: [`this.getField("Text6").value = "PageClose 3";`],
      });
      await loadingTask.destroy();
    });
    it("gets non-existent outline", async function () {
      const loadingTask = getDocument(
        buildGetDocumentParams("tracemonkey.pdf")
      );
      const pdfDoc = await loadingTask.promise;
      const outline = await pdfDoc.getOutline();