Move all C++ tests to cpp.

cpp/test_const_arg.cpp

@@ -0,0 +1,52 @@
+
+#include <iostream>
+
+void f ( int& i )
+{
+	std::cout << "int" << std::endl;
+}
+
+void f ( const int& i )
+{
+	std::cout << "const int" << std::endl;
+}
+
+#if 0
+void f ( volatile int& i )
+{
+	std::cout << "volatile int" << std::endl;
+}
+
+void f ( const volatile int& i )
+{
+	std::cout << "const volatile int" << std::endl;
+}
+#endif
+
+int g ( )
+{
+	int i = 2;
+	return i;
+}
+
+int main( void )
+{
+#if 0
+	const volatile int cvi = 1;
+	f( cvi );
+
+	volatile int vi = 1;
+	f( vi );
+#endif
+	
+	const int ci = 1;
+	f( ci );
+
+	int i = 1;
+	f( i );
+
+	f( g() );
+
+	return 0;
+}
+