Enable some C++ tests by just using a different namespace

Using "typename" or "dynamic_cast" as C++ namespace names unsurprisingly
resulted in compilation errors, so don't do this.

Examples/test-suite/c/Makefile.in

@@ -123,7 +123,6 @@ director_conversion_operators.cpptest \
 director_frob.cpptest \
 director_property.cpptest \
 director_string.cpptest \
-dynamic_cast.cpptest \
 extend_template_method.cpptest \
 features.cpptest \
 global_namespace.cpptest \
@@ -189,14 +188,19 @@ template_typedef_cplx5.cpptest \
 template_typemaps.cpptest \
 template_typemaps_typedef.cpptest \
 template_typemaps_typedef2.cpptest \
-typename.cpptest \
 valuewrapper_const.cpptest \
 valuewrapper_opaque.cpptest \
 : SWIGOPT += -nocxx
 
+# Avoid conflict with the C++ keyword for some tests.
+SWIG_NS = $*
+
+dynamic_cast.cpptest: SWIG_NS = dyn_cast
+typename.cpptest: SWIG_NS = type_name
+
 %.multicpptest: SWIGOPT += -namespace $*
 
-%.cpptest: SWIGOPT += -namespace $*
+%.cpptest: SWIGOPT += -namespace $(SWIG_NS)
 
 SRCDIR       = ../$(srcdir)/