virtualp - determine whether or not a given variable points to a virtual object

int virtualp( object arg );

Returns true (1) if the argument is objectp() and the O_VIRTUAL flag is set.
The driver sets the O_VIRTUAL flag for those objects created via the
'compile_object' function in the master object.

 Tim Hollebeek  Beek@ZorkMUD, Lima Bean, IdeaExchange, and elsewhere
