Auto-configure '-slabs' values (#1276)

- Auto-configure '-slabs' values to a power of 2 value close to num-threads
  by default for multi-threaded environments.

Co-authored-by: Wouter Wijngaards <wcawijngaards@users.noreply.github.com>

testcode/unitauth.c

@@ -670,6 +670,7 @@ authtest_addzone(struct auth_zones* az, const char* name, char* fname)
 	auth_zone_set_zonefile(z, fname);
 	z->for_upstream = 1;
 	cfg = config_create();
+	config_auto_slab_values(cfg);
 	free(cfg->chrootdir);
 	cfg->chrootdir = NULL;
 

testcode/unitinfra.c

@@ -131,6 +131,7 @@ void infra_test(void)
 	unit_show_feature("infra cache");
 	unit_assert(ipstrtoaddr("127.0.0.1", 53, &one, &onelen));
 
+	config_auto_slab_values(cfg);
 	slab = infra_create(cfg);
 	/* insert new record */
 	unit_assert( infra_host(slab, &one, onelen, zone, zonelen, now,

testcode/unitzonemd.c

@@ -267,6 +267,7 @@ static void zonemd_verify_test(char* zname, char* zfile, char* tastr,
 	env.cfg = config_create();
 	if(!env.cfg)
 		fatal_exit("out of memory");
+	config_auto_slab_values(env.cfg);
 	env.now = &now;
 	env.cfg->val_date_override = cfg_convert_timeval(date_override);
 	if(!env.cfg->val_date_override)