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):

const loadingTask = getDocument(buildGetDocumentParams("issue6106.pdf"));
      const pdfDoc = await loadingTask.promise;
      const javascript = await pdfDoc.getJavaScript();
      expect(javascript).toEqual([
        "this.print({bUI:true,bSilent:false,bShrinkToFit:true});",
      ]);
      expect(javascript[0]).toMatch(AutoPrintRegExp);
      await loadingTask.destroy();
    });
    it("gets hasJSActions, in document without javaScript", async function () {
      const hasJSActions = await pdfDocument.hasJSActions();
      expect(hasJSActions).toEqual(false);
    });
    it("gets hasJSActions, in document with javaScript", async function () {
      const loadingTask = getDocument(
        buildGetDocumentParams("doc_actions.pdf")
      );
      const pdfDoc = await loadingTask.promise;
      const hasJSActions = await pdfDoc.hasJSActions();
      expect(hasJSActions).toEqual(true);
      await loadingTask.destroy();
    });
    it("gets non-existent JSActions", async function () {
      const jsActions = await pdfDocument.getJSActions();
      expect(jsActions).toEqual(null);
    });
    it("gets JSActions", async function () {
      
      const loadingTask = getDocument(
        buildGetDocumentParams("doc_actions.pdf")