bug#29557: lookup_basic_face: Should we add VERTICAL_BORDER_FACE_ID?

[Keith David Bershatsky]

I had assumed that VERTICAL_BORDER_FACE_ID was a basic face (see dispextern.h 
at line 1750).  However, it is not identified as such within lookup_basic_face. 
 Is this something that should be added?  Without it, Emacs will throw an error 
if someone tries to look it up and its not there.

case VERTICAL_BORDER_FACE_ID: name = Qvertical_border; break;

Thanks,

Keith