Make base class IsXternSegment() return false.

Former-commit-id: af82c76b188751e09224de631848a94cd246fe02

include/interfaces/abstract/STARSSegment.h

@@ -12,7 +12,7 @@ class STARS_Segment_t
 
 		/* figure out what kind of segment this is */
 		virtual bool IsCodeSegment() =0 ;
-		virtual bool IsXternSegment() =0 ;
+		virtual bool IsXternSegment() { return false; };
 		virtual bool IsDataSegment() =0 ;
 		virtual bool IsCommonSegment() =0 ;
 		virtual bool IsBSSSegment() =0 ;