C++: Add test with missing result.

cpp/ql/test/experimental/query-tests/Security/CWE/CWE-570/semmle/tests/test.cpp

@@ -205,4 +205,10 @@ void bad_new_with_nonthrowing_call() {
     Foo f;
     if(f) { }
   } catch(...) {  }
-}
+}
+
+void bad_new_catch_baseclass_of_bad_alloc() {
+  try {
+    int* p = new(std::nothrow) int; // BAD [NOT DETECTED]
+  } catch(const std::exception&) { }
+}