utest: move cpp from examples to components/libc/cplusplus

Also update the case names to compatible with naming rules.

Signed-off-by: Chen Wang <unicorn_wang@outlook.com>

components/libc/cplusplus/utest/tc_smartptr.cpp

@@ -0,0 +1,55 @@
+/*
+ * Copyright (c) 2006-2025, RT-Thread Development Team
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2025-09-19     Rbb666       the first version
+ */
+
+#include <rtthread.h>
+#include "utest.h"
+#include <memory>
+
+/**
+ * @brief Test unique_ptr basic operations.
+ */
+static void test_unique_ptr(void)
+{
+    std::unique_ptr<int> p(new int(42));
+    uassert_int_equal(*p, 42);
+    *p = 24;
+    uassert_int_equal(*p, 24);
+}
+
+/**
+ * @brief Test shared_ptr basic operations.
+ */
+static void test_shared_ptr(void)
+{
+    std::shared_ptr<int> p1(new int(42));
+    std::shared_ptr<int> p2 = p1;
+    uassert_int_equal(*p1, 42);
+    uassert_int_equal(*p2, 42);
+    uassert_int_equal(p1.use_count(), 2);
+}
+
+static rt_err_t utest_tc_init(void)
+{
+    return RT_EOK;
+}
+
+static rt_err_t utest_tc_cleanup(void)
+{
+    return RT_EOK;
+}
+
+static void testcase(void)
+{
+    /* Test unique_ptr basic operations */
+    UTEST_UNIT_RUN(test_unique_ptr);
+    /* Test shared_ptr basic operations */
+    UTEST_UNIT_RUN(test_shared_ptr);
+}
+UTEST_TC_EXPORT(testcase, "components.libc.cpp.smartptr_tc", utest_tc_init, utest_tc_cleanup, 10);