Attach (recommended) or Link to PDF file here:
https://www.nta.go.jp/taxes/tetsuzuki/shinsei/annai/joyaku/annai/pdf2/250.pdf

Configuration:
- Web browser and its version: Firefox 81.0a1
- Operating system and its version: Debian 5.6.7-1
- PDF.js version: latest in Firefox nightly
- Is a browser extension: No

Steps to reproduce the problem:
1. Open the pdf and paste the following text "本 店 又 は 主 た る 事 務 所 の 所 在 地" in "Full name" and in "Domicile and residence" textfields
2. Print or Save the pdf 

What is the expected behavior? (add screenshot)
![image](https://user-images.githubusercontent.com/5641725/91207547-30f05480-e709-11ea-9abd-2af5d970dc46.png)

What went wrong? (add screenshot)
![image](https://user-images.githubusercontent.com/5641725/91207663-69902e00-e709-11ea-8a1d-1ddd30cf0621.png)

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

textWidgetRef,
        pdfManagerMock,
        idFactoryMock
      )
        .then(annotation => {
          const id = annotation.data.id;
          const annotationStorage = {};
          annotationStorage[id] = { value: "aa(aa)a\\" };
          return annotation._getAppearance(
            partialEvaluator,
            task,
            annotationStorage
          );
        }, done.fail)
        .then(appearance => {
          expect(appearance).toEqual(
            "/Tx BMC q BT /Helv 5 Tf 1 0 0 1 2 2 Tm" +
              " (a) Tj 8.00 0 Td (a) Tj 8.00 0 Td (\\() Tj" +
              " 8.00 0 Td (a) Tj 8.00 0 Td (a) Tj" +
              " 8.00 0 Td (\\)) Tj 8.00 0 Td (a) Tj" +
              " 8.00 0 Td (\\\\) Tj ET Q EMC"
          );
          done();
        }, done.fail);
    });
    it("should save text", function (done) {
      const textWidgetRef = Ref.get(123, 0);
      const xref = new XRefMock([{ ref: textWidgetRef, data: textWidgetDict }]);
      partialEvaluator.xref = xref;
      const task = new WorkerTask("test save");