stdlib: merge some tests from gnulib

This makes the tests the same in both places. The changes in Gnulib
brought in by this patch also silence -Woverflow when using gcc 16.1.1
on i686.

Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>

SHARED-FILES

@@ -113,6 +113,7 @@ gnulib:
   stdlib/setenv.c
   stdlib/strtoll.c
   stdlib/strtoul.c
+  # Merged from gnulib 2026-08-27, (gnulib commit ec224ee81b)
   stdlib/tst-stdc_rotate_left.c
   stdlib/tst-stdc_rotate_right.c
   # Merged from gnulib 2014-6-26, needs merge back

stdlib/tst-stdc_rotate_left.c

@@ -15,8 +15,27 @@
    License along with the GNU C Library; if not, see
    <https://www.gnu.org/licenses/>.  */
 
+#ifdef GNULIB_TEST_STDBIT
+# include <config.h>
+#endif
+
+/* Specification.  */
 #include <stdbit.h>
-#include <support/check.h>
+
+#include <limits.h>
+
+#ifdef GNULIB_TEST_STDBIT
+# include "macros.h"
+# define MAIN_STATIC
+# define MAIN main
+# define TEST_COMPARE(a, b) ASSERT ((a) == (b))
+# define TEST_EXIT_STATUS test_exit_status
+#else
+# include <support/check.h>
+# define MAIN_STATIC static
+# define MAIN do_test
+# define TEST_EXIT_STATUS 0
+#endif
 
 #define TEST_CASE(type, function, value, shift, expect)         \
   do                                                            \
@@ -431,10 +450,11 @@ test_stdc_rotate_left_ui (void)
 static void
 test_stdc_rotate_left_ul (void)
 {
-  if (sizeof 0ul < sizeof 0ull)
+#if ULONG_MAX >> 31 == 1
-    TEST_CASES_32 (unsigned long int, stdc_rotate_left_ul);
+  TEST_CASES_32 (unsigned long int, stdc_rotate_left_ul);
-  else
+#else
-    TEST_CASES_64 (unsigned long long int, stdc_rotate_left_ul);
+  TEST_CASES_64 (unsigned long int, stdc_rotate_left_ul);
+#endif
 }
 
 static void
@@ -443,15 +463,17 @@ test_stdc_rotate_left_ull (void)
   TEST_CASES_64 (unsigned long long int, stdc_rotate_left_ull);
 }
 
-static int
+MAIN_STATIC int
-do_test (void)
+MAIN (void)
 {
   test_stdc_rotate_left_uc ();
   test_stdc_rotate_left_us ();
   test_stdc_rotate_left_ui ();
   test_stdc_rotate_left_ul ();
   test_stdc_rotate_left_ull ();
-  return 0;
+  return TEST_EXIT_STATUS;
 }
 
-#include <support/test-driver.c>
+#ifndef GNULIB_TEST_STDBIT
+# include <support/test-driver.c>
+#endif

stdlib/tst-stdc_rotate_right.c

@@ -15,8 +15,27 @@
    License along with the GNU C Library; if not, see
    <https://www.gnu.org/licenses/>.  */
 
+#ifdef GNULIB_TEST_STDBIT
+# include <config.h>
+#endif
+
+/* Specification.  */
 #include <stdbit.h>
-#include <support/check.h>
+
+#include <limits.h>
+
+#ifdef GNULIB_TEST_STDBIT
+# include "macros.h"
+# define MAIN_STATIC
+# define MAIN main
+# define TEST_COMPARE(a, b) ASSERT ((a) == (b))
+# define TEST_EXIT_STATUS test_exit_status
+#else
+# include <support/check.h>
+# define MAIN_STATIC static
+# define MAIN do_test
+# define TEST_EXIT_STATUS 0
+#endif
 
 #define TEST_CASE(type, function, value, shift, expect)         \
   do                                                            \
@@ -431,10 +450,11 @@ test_stdc_rotate_right_ui (void)
 static void
 test_stdc_rotate_right_ul (void)
 {
-  if (sizeof 0ul < sizeof 0ull)
+#if ULONG_MAX >> 31 == 1
-    TEST_CASES_32 (unsigned long int, stdc_rotate_right_ul);
+  TEST_CASES_32 (unsigned long int, stdc_rotate_right_ul);
-  else
+#else
-    TEST_CASES_64 (unsigned long long int, stdc_rotate_right_ul);
+  TEST_CASES_64 (unsigned long int, stdc_rotate_right_ul);
+#endif
 }
 
 static void
@@ -443,15 +463,17 @@ test_stdc_rotate_right_ull (void)
   TEST_CASES_64 (unsigned long long int, stdc_rotate_right_ull);
 }
 
-static int
+MAIN_STATIC int
-do_test (void)
+MAIN (void)
 {
   test_stdc_rotate_right_uc ();
   test_stdc_rotate_right_us ();
   test_stdc_rotate_right_ui ();
   test_stdc_rotate_right_ul ();
   test_stdc_rotate_right_ull ();
-  return 0;
+  return TEST_EXIT_STATUS;
 }
 
-#include <support/test-driver.c>
+#ifndef GNULIB_TEST_STDBIT
+# include <support/test-driver.c>
+#endif