GC_CAN_SAVE_CALL_STACKS  480 gc/include/gc.h #   define GC_CAN_SAVE_CALL_STACKS
GC_CAN_SAVE_CALL_STACKS  485 gc/include/gc.h # define GC_CAN_SAVE_CALL_STACKS
GC_CAN_SAVE_CALL_STACKS  489 gc/include/gc.h #   define GC_CAN_SAVE_CALL_STACKS