https://boersengefluester.de/wp-content/uploads/assets/annuals/2019/578560.pdf

Configuration:
- PDF.js version: 2.7.570

Steps to reproduce the problem:
1. Load the linked PDF
2. On the second page, highlight the word "Mitarbeiterinnen" by double-clicking it

What is the expected behavior?
The word should be recognized as a single word and highlighted as such.

What went wrong?
Instead, it's recognized as 3 words: "Mit", "arbei", "terinnen"
![image](https://user-images.githubusercontent.com/5265630/114384414-f8fe2a80-9b8e-11eb-8843-5099425b0fad.png)

This happens for many words in this PDF.

Is there anything that can be changed in how I use pdfjs-dist to make it recognize this as a single word? Just looking at the PDF, I can't tell what would cause this behavior.

buildGetDocumentParams("issue8702.pdf", {
            stopAtErrors: true,
          })
        );
        const result1 = loadingTask1.promise.then(pdfDoc => {
          return pdfDoc.getPage(1).then(pdfPage => {
            return pdfPage.getOperatorList().then(opList => {
              expect(opList.fnArray.length).toBeGreaterThan(100);
              expect(opList.argsArray.length).toBeGreaterThan(100);
              expect(opList.lastChunk).toEqual(true);
              return loadingTask1.destroy();
            });
          });
        });
        const result2 = loadingTask2.promise.then(pdfDoc => {
          return pdfDoc.getPage(1).then(pdfPage => {
            return pdfPage.getOperatorList().then(opList => {
              expect(opList.fnArray.length).toEqual(0);
              expect(opList.argsArray.length).toEqual(0);
              expect(opList.lastChunk).toEqual(true);
              return loadingTask2.destroy();
            });
          });
        });
        await Promise.all([result1, result2]);
      }
    );
    it("gets operator list, containing Annotation-operatorLists", async function () {
      const loadingTask = getDocument(
        buildGetDocumentParams("annotation-line.pdf")