Macros starting with `b' in arch/i386/isa

• BDBTRAP arch/i386/isa/debug.h:11
• bt_abortmbx arch/i386/isa/bt742a.c:433
• bt_startmbx arch/i386/isa/bt742a.c:436
• BUILD_FAST_VECTOR arch/i386/isa/vector.s:185
• BUILD_VECTOR arch/i386/isa/vector.s:195