SP_SLOP           991 gc/pthread_support.c 	me -> backing_store_ptr = (ptr_t)GC_save_regs_in_stack() + SP_SLOP;
SP_SLOP           997 gc/pthread_support.c 	me -> stop_info.stack_ptr += SP_SLOP;
SP_SLOP           999 gc/pthread_support.c 	me -> stop_info.stack_ptr -= SP_SLOP;