alue from the this
   pointer. Always non-NULL, might be constant zero though.  */
#define BV_DELTA(NODE) (TREE_PURPOSE (NODE))

/* If non-NULL, the vtable index at which to find the vcall offset
   when calling this virtual function.  Add the value at that vtable
   index to the this pointer.  */
#define BV_VCALL_INDEX(NODE) (TREE_TYPE (NODE))

/* The function to call.  */
#define BV_FN(NODE) (TREE_VALUE (NODE))

/* Whether or not this entry is for a lost primary virtual base.  */
#define BV_LOST_PRIMARY(NODE) (TREE_LANG_FLAG_0 (NODE))