Attach (recommended) or Link to PDF file here:
[jpa2021506744.pdf](https://github.com/mozilla/pdf.js/files/6431655/jpa2021506744.pdf)

Configuration:
- Web browser and its version: Google Chrome v89.0.4389.114 /IE ver 20H2 (OS build 19042.928)/Microsoft Edge 89.0.774.77 (64 bit)
- Operating system and its version: Windows 10 Pro 20H2 19042.928
- PDF.js version: 2.7.570
- Is a browser extension: No

Steps to reproduce the problem:
As you can see from the attached jpa2021506744 [jpa2021506744.pdf](https://github.com/mozilla/pdf.js/files/6431655/jpa2021506744.pdf)  page 15,
When using PDF.js, the  text is cut off on Japanese documents.
What went wrong? I hope to solve this problem.

I tried to improve after seeing these pages.

https://github.com/mozilla/pdf.js/issues/12110
https://github.com/mozilla/pdf.js/pull/13067

Adobe Reader does not have this problem.


What is the expected behavior? (add screenshot)
![jpa_2021_506744_OK](https://user-images.githubusercontent.com/82868736/117239725-473eda80-ae6a-11eb-8de6-1f96250b8351.jpg)

What went wrong? (add screenshot)
![jpa_2021_506744_NG](https://user-images.githubusercontent.com/82868736/117239739-4dcd5200-ae6a-11eb-8db9-61b33088574c.jpg)

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

}
        }
      }
    } ele {
      cnt frtChar = prperte.frtChar;
      wdth = dct.get("Wdth");
      f (wdth) {
        j = frtChar;
        fr ( = 0,  = wdth.length;  < ; ) {
          glyphWdth[j] = xref.fetchIfRef(wdth[]);
        }
        defaultWdth = pareFlat(decrptr.get("MngWdth")) || 0;
      } ele {
         Tryng get the BaeFnt metrc (ee cmment abve).
        cnt baeFntName = dct.get("BaeFnt");
        f (Name(baeFntName)) {
          cnt metrc = th.getBaeFntMetrc(baeFntName.name);
          glyphWdth = th.buldCharCdeTWdth(metrc.wdth, prperte);
          defaultWdth = metrc.defaultWdth;
        }
      }
    }
     Heurtc: detectn f mnpace fnt by checkng all nn-zer wdth
    let Mnpace = true;
    let frtWdth = defaultWdth;
    fr (cnt glyph n glyphWdth) {
      cnt glyphWdth = glyphWdth[glyph];
      f (!glyphWdth) {
        cntnue;
      }