Duplicate tests that are run twice as both C and C++ tests to fix parallel make: li_cdata

Examples/test-suite/li_cdata_cpp.i

@@ -0,0 +1,8 @@
+%module li_cdata_cpp
+
+%include <cdata.i>
+
+%cdata(int);
+%cdata(double);
+
+void *malloc(size_t size);