Attach (recommended) or Link to PDF file here:

Configuration:
- Web browser and its version: Chrome 63.0.3239.132 
- Operating system and its version: Windows 10
- PDF.js version: using your official demo project
- Is a browser extension: No

Steps to reproduce the problem:
1.  Just load attached pdf
2.

What is the expected behavior? (add screenshot)
[E-WG18_105147.pdf](https://github.com/mozilla/pdf.js/files/1634833/E-WG18_105147.pdf)

What went wrong? (add screenshot)
![image](https://user-images.githubusercontent.com/29802177/34986271-3ca71a5c-fab7-11e7-95e8-1739dda3cd04.png)

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

}
      if (lastCharIndex < code) {
        lastCharIndex = code;
      }
      const position = getUnicodeRangeFor(code);
      if (position < 32) {
        ulUnicodeRange1 |= 1 << position;
      } else if (position < 64) {
        ulUnicodeRange2 |= 1 << (position - 32);
      } else if (position < 96) {
        ulUnicodeRange3 |= 1 << (position - 64);
      } else if (position < 123) {
        ulUnicodeRange4 |= 1 << (position - 96);
      } else {
        throw new FormatError(
          "Unicode ranges Bits > 123 are reserved for internal usage"
        );
      }
    }
    if (lastCharIndex > 0xffff) {
      
      
      lastCharIndex = 0xffff;
    }
  } else {
    
    firstCharIndex = 0;
    lastCharIndex = 255;
  }
  const bbox = properties.bbox || [0, 0, 0, 0];