add creat test

Tesing commit f7e53f9b00.

programs/tests/CMakeLists.txt

@@ -1,5 +1,6 @@
 # List of programs.
 set(TEST_LIST
+    t_creat.c
     t_write_read.c
     t_gid.c
     t_alarm.c

programs/tests/t_creat.c

@@ -0,0 +1,37 @@
+/// @file t_creat.c
+/// @brief test the creat syscall
+/// @copyright (c) 2024 This file is distributed under the MIT License.
+/// See LICENSE.md for details.
+
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <strerror.h>
+#include <sys/errno.h>
+#include <sys/stat.h>
+#include <sys/unistd.h>
+
+int main(int argc, char* argv[]) {
+	int fd = creat("foo", 0660);
+	if (fd < 0) {
+		printf("creat: foo: %s\n", strerror(errno));
+		exit(EXIT_FAILURE);
+	}
+	if (write(fd, "foo", 3) != 3) {
+		printf("write: foo: %s\n", strerror(errno));
+		exit(EXIT_FAILURE);
+	}
+
+	struct stat_t st;
+	if (stat("foo", &st) < 0) {
+		printf("stat: foo: %s\n", strerror(errno));
+		exit(EXIT_FAILURE);
+	}
+
+	if (st.st_size != 3) {
+		printf("Wrong file size. (expected: 3, is: %u)\n", st.st_size);
+		exit(EXIT_FAILURE);
+	}
+
+	return 0;
+}