test: add example that leads preprocessor to a dead loop

Signed-off-by: Efimov Vasily <[email protected]>

test/testcpp.py

@@ -68,4 +68,19 @@ def test_concatenation(self):
 _qs_"""
         )
 
+    def test_deadloop_macro(self):
+        # If there is a word which equals to name of a parametrized macro, then
+        # attempt to expand such word as a macro manages the parser to fall
+        # into an infinite loop.
+
+        self.__test_preprocessing("""\
+#define a(x) x
+
+a;"""
+            , """\
+
+
+a;"""
+        )
+
 main()