Attach (recommended) or Link to PDF file here:
[Hong Kong Aircraft Engineering Company Limited_1511417616.1 2.pdf](https://github.com/mozilla/pdf.js/files/1539395/Hong.Kong.Aircraft.Engineering.Company.Limited_1511417616.1.2.pdf)


Configuration:
- Web browser and its version: Chrome: 63 
- Operating system and its version: windows and macOs
- PDF.js version: 2.0.185
- Is a browser extension: No

Steps to reproduce the problem:
1. Upload the above PDF and search for "article 1"
2. PDF.js showing only **2** match But actually **4** times available.   

What is the expected behavior? (add screenshot)

![screen shot 2017-12-07 at 7](https://user-images.githubusercontent.com/6101789/33720106-ed404576-db88-11e7-9c19-cf6aea74e9f3.png)



What went wrong? (add screenshot)

Link to a viewer (if hosted on a site other than mozilla.github.io/pdf.js or as Firefox/Chrome extension):

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")