tests, samples: Define _POSIX_C_SOURCE where needed

Various tests and samples use POSIX-only functions. Define _POSIX_C_SOURCE
to ensure they are visible.

Signed-off-by: Keith Packard <[email protected]>

Author: keith-packard

samples/posix/gettimeofday/src/main.c

@@ -4,6 +4,8 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
+#undef _POSIX_C_SOURCE
+#define _POSIX_C_SOURCE 200809L
 #include <stdio.h>
 #include <stdlib.h>
 #include <errno.h>

tests/lib/c_lib/common/src/main.c

@@ -15,10 +15,8 @@
  * it guarantee that ALL functionality provided is working correctly.
  */
 
-#if defined(CONFIG_NATIVE_LIBC)
 #undef _POSIX_C_SOURCE
 #define _POSIX_C_SOURCE 200809L
-#endif
 
 #include <zephyr/kernel.h>
 #include <zephyr/sys/__assert.h>

tests/posix/fs/src/test_fs_dir.c

@@ -4,6 +4,9 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
+#undef _POSIX_C_SOURCE
+#define _POSIX_C_SOURCE 200809L
+
 #include <stdio.h>
 #include <fcntl.h>
 #include <zephyr/posix/unistd.h>

tests/posix/fs/src/test_fs_stat.c

@@ -4,6 +4,9 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
+#undef _POSIX_C_SOURCE
+#define _POSIX_C_SOURCE 200809L
+
 #include <string.h>
 #include <zephyr/posix/fcntl.h>
 #include <zephyr/posix/unistd.h>