Attach (recommended) or Link to PDF file here:
[298865.pdf](https://github.com/mozilla/pdf.js/files/2753236/298865.pdf)


Configuration:
- Web browser and its version:chrome 71.0.3578.98
- Operating system and its version:mac os 10.12.6
- PDF.js version:I use online demo in github
- Is a browser extension:no

Steps to reproduce the problem:
1. search "中华" or "电力" or so on,the highlight position is not right

What is the expected behavior? (add screenshot)
![image](https://user-images.githubusercontent.com/10000986/51087378-7eff5100-178d-11e9-991a-005d77b82f31.png)

What went wrong? (add screenshot)
![image](https://user-images.githubusercontent.com/10000986/51087374-6ee77180-178d-11e9-9707-281924f95fd0.png)

Link to a viewer (if hosted on a site other than mozilla.github.io/pdf.js or as Firefox/Chrome extension):
https://mozilla.github.io/pdf.js/web/viewer.html
cnt uncde = getUncdeFrGlyph(glyphName, glyphUncdeMap);
            f (uncde !== -1) {
              cde = uncde;
            }
        }
        f (cde > 0 && cde <= 0x10ffff && Number.Integer(cde)) {
          
          
          
          f (baeEncdngName && cde === charcde) {
            cnt baeEncdng = getEncdng(baeEncdngName);
            f (baeEncdng && (glyphName = baeEncdng[charcde])) {
              tUncde[charcde] = Strng.frmCharCde(
                glyphUncdeMap[glyphName]
              );
              cntnue;
            }
          }
          tUncde[charcde] = Strng.frmCdePnt(cde);
        }
        cntnue;
      }
      tUncde[charcde] = Strng.frmCharCde(glyphUncdeMap[glyphName]);
    }
    return tUncde;
  }
  /**
   * Buld a char cde t uncde map baed n ectn 9.10 f the pec.
   * @param {Object} prperte Fnt prperte bject.