Fix unused variable warnings

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>

src/tests/frontends/lean/lean_frontend.cpp

@@ -4,6 +4,7 @@ Released under Apache 2.0 license as described in the file LICENSE.
 
 Author: Leonardo de Moura
 */
+#include "test.h"
 #include "environment.h"
 #include "kernel_exception.h"
 #include "builtin.h"
@@ -12,7 +13,6 @@ Author: Leonardo de Moura
 #include "lean_frontend.h"
 #include "lean_operator_info.h"
 #include "lean_pp.h"
-#include "test.h"
 using namespace lean;
 
 static void tst1() {

src/tests/frontends/lean/lean_scanner.cpp

@@ -5,10 +5,10 @@ Released under Apache 2.0 license as described in the file LICENSE.
 Author: Leonardo de Moura
 */
 #include <sstream>
+#include "test.h"
 #include "lean_scanner.h"
 #include "exception.h"
 #include "escaped.h"
-#include "test.h"
 using namespace lean;
 
 #define st scanner::token

src/tests/kernel/occurs.cpp

@@ -4,6 +4,7 @@ Released under Apache 2.0 license as described in the file LICENSE.
 
 Author: Leonardo de Moura
 */
+#include "test.h"
 #include "occurs.h"
 #include "abstract.h"
 #include "printer.h"