/* structure of the stacks */ #ifndef _stacks_#define _stacks_  #include "misc.h"#include "mlvalues.h"#include "memory.h" extern value * stack_low;extern value * stack_high;extern value * stack_threshold;extern value * extern_sp;extern value * trapsp; extern value global_data; #define Trap_pc(tp) (((CODE *)(tp))[0])#define Trap_link(tp) (((value **)(tp))[1]) void reset_roots (void);void init_stack (void);void realloc_stack (void);  #endif /* _stacks_ */