Hack for "true" and "false" used as enum element values

This is not a full solution by far, but should address the most common case.

This also allows "cpp_enum" unit test to pass.

Examples/test-suite/c/Makefile.in

@@ -51,7 +51,6 @@ FAILING_CPP_TESTS := \
     cpp_basic_global_var_class \
     cpp_basic_template_class \
     cpp_basic_template_function \
-    cpp_enum \
     c_backend_cpp_natural_std_string \
     c_backend_cpp_exception \
     default_args \

Examples/test-suite/c/cpp_enum_runme.c

@@ -63,10 +63,10 @@ int main(int argc, const char *argv[]) {
 	play_state t;
 
 	t = PLAY;
-	assert(t == true);
+	assert(t == 1);
 
 	t = STOP;
-	assert(t == false);
+	assert(t == 0);
 
 	return 0;
-}
+}