refactor: rename testbench to test.

- rename testbench to test.
- add benchmark for future development.

test/yycc/macro/os_detector.cpp

@@ -0,0 +1,20 @@
+#include <gtest/gtest.h>
+#include <yycc.hpp>
+#include <yycc/macro/os_detector.hpp>
+
+#define OS ::yycc::macro::os
+
+namespace yycctest::macro::os {
+
+    TEST(MacroOs, Main) {
+        auto rv = OS::get_os();
+#if defined(YYCC_OS_WINDOWS)
+        EXPECT_EQ(rv, OS::OsKind::Windows);
+#elif defined(YYCC_OS_LINUX)
+        EXPECT_EQ(rv, OS::OsKind::Linux);
+#else
+        EXPECT_EQ(rv, OS::OsKind::MacOs);
+#endif
+    }
+
+} // namespace yycctest::macro::os