Testing: added an option for benchmark version of the test

static int no_fork;

static int no_timeout;

static int is_terminal;		/* Whether stdout is a live terminal or pipe redirect */

int benchmark;			/* Whether we shall run the benchmark test version */

uint bt_verbose;

const char *bt_filename;

  bt_test_id = NULL;

  is_terminal = isatty(fileno(stdout));

  while ((c = getopt(argc, argv, "lcdftv")) >= 0)

  while ((c = getopt(argc, argv, "blcdftv")) >= 0)

    switch (c)

    {

      case 'b':

	benchmark = 1;

	break;

      case 'l':

	list_tests = 1;

	break;

#include "nest/bird.h"

extern int benchmark;

extern int bt_result;

extern int bt_suite_result;