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)

let bufferLength = this.bufferLength;
      if (n === 32) {
        if (bufferLength === 0) {
          return (
            ((this.stream.getByte() << 24) |
              (this.stream.getByte() << 16) |
              (this.stream.getByte() << 8) |
              this.stream.getByte()) >>>
            0
          );
        }
        buffer =
          (buffer << 24) |
          (this.stream.getByte() << 16) |
          (this.stream.getByte() << 8) |
          this.stream.getByte();
        const nextByte = this.stream.getByte();
        this.buffer = nextByte & ((1 << bufferLength) - 1);
        return (
          ((buffer << (8 - bufferLength)) |
            ((nextByte & 0xff) >> bufferLength)) >>>
          0
        );
      }
      if (n === 8 && bufferLength === 0) {
        return this.stream.getByte();
      }
      while (bufferLength < n) {
        buffer = (buffer << 8) | this.stream.getByte();
        bufferLength += 8;