Attach (recommended) or Link to PDF file here:

Configuration:
- Web browser and its version: Chrome 90.0.4430.93
- Operating system and its version: macOs Big Sur 11.2.3
- PDF.js version: 2.7.570
- Is a browser extension: No

Steps to reproduce the problem:
1. Load the attached pdf in https://mozilla.github.io/pdf.js/web/viewer.html
2. Go to page 46. Dotted lines are missing in the graphics (see screenshot from acrobat reader)

What is the expected behavior? (add screenshot) See the screenshot
[Technical_Guide_UK.pdf](https://github.com/mozilla/pdf.js/files/6413001/Technical_Guide_UK.pdf)
![Screenshot 2021-05-03 at 07 46 09](https://user-images.githubusercontent.com/3785784/116844541-a343fd80-abe3-11eb-94c3-d03b3dfd6769.png)

case 2:
          tmp1 = ps[15];
          tmp2 = ps[11];
          ps[12] = ps[3];  ps[13] = pi + 0; ps[14] = pi + 1;   ps[15] = pi + 2;
          ps[ 8] = ps[7];   ps[11] = pi + 3;
          ps[ 4] = tmp2;    ps[ 7] = pi + 4;
          ps[ 0] = tmp1;  ps[ 1] = pi + 7;   ps[ 2] = pi + 6;  ps[ 3] = pi + 5;
          tmp1 = cs[3];
          cs[2] = cs[1]; cs[3] = ci;
          cs[0] = tmp1;  cs[1] = ci + 1;
          break;
        
        case 3:
          ps[12] = ps[0];  ps[13] = pi + 0;   ps[14] = pi + 1; ps[15] = pi + 2;
          ps[ 8] = ps[1];   ps[11] = pi + 3;
          ps[ 4] = ps[2];   ps[ 7] = pi + 4;
          ps[ 0] = ps[3];  ps[ 1] = pi + 7;   ps[ 2] = pi + 6; ps[ 3] = pi + 5;
          cs[2] = cs[0]; cs[3] = ci;
          cs[0] = cs[1]; cs[1] = ci + 1;
          break;
      }
      
      ps[5] = coords.length;
      coords.push([
        (-4 * coords[ps[0]][0] -
          coords[ps[15]][0] +
          6 * (coords[ps[4]][0] + coords[ps[1]][0]) -
          2 * (coords[ps[12]][0] + coords[ps[3]][0]) +
          3 * (coords[ps[13]][0] + coords[ps[7]][0])) /
          9,