T_IBREAK
case T_IBREAK:
if (trapnum != T_INTERRUPT && trapnum != T_IBREAK)
else if (trapnum == T_IBREAK)
case T_IBREAK:
if (type == T_IBREAK) {
case T_IBREAK | T_USER:
#define IS_BREAKPOINT_TRAP(type, code) ((type) == T_IBREAK)