void *p = PORT_ArenaAlloc(arena, size);
void *p;  if (size <= 0) size = 1;  p = PORT_ArenaAlloc(arena, size);
PORT_ArenaZAlloc(PLArenaPool *arena, size_t size){    void *p = PORT_ArenaAlloc(arena, size);    if (p) {	PORT_Memset(p, 0, size);    }    return(p);}