Add test for 57a35bf fix

So it turns out that the fix stops the engine from crashing, but it
still doesn't seem to generate valid code - Aul emits an internal error
at runtime.

tests/CMakeLists.txt

@@ -120,6 +120,7 @@ if (GTEST_FOUND AND GMOCK_FOUND)
 			aul/AulTest.h
 			aul/AulMathTest.cpp
 			aul/AulPredefinedFunctionTest.cpp
+			aul/AulDeathTest.cpp
             ../src/script/C4ScriptStandaloneStubs.cpp
             ../src/script/C4ScriptStandalone.cpp
         LIBRARIES

tests/aul/AulDeathTest.cpp

@@ -0,0 +1,37 @@
+/*
+* OpenClonk, http://www.openclonk.org
+*
+* Copyright (c) 2016, The OpenClonk Team and contributors
+*
+* Distributed under the terms of the ISC license; see accompanying file
+* "COPYING" for details.
+*
+* "Clonk" is a registered trademark of Matthes Bender, used with permission.
+* See accompanying file "TRADEMARK" for details.
+*
+* To redistribute this file separately, substitute the full license texts
+* for the above references.
+*/
+
+// Testing C4Aul behaviour.
+
+#include "C4Include.h"
+#include "AulTest.h"
+
+#include <cstdlib>
+#include "script/C4Aul.h"
+
+class AulDeathTest : public AulTest
+{};
+
+// DEATH_SUCCESS_CODE is arbitrarily chosen such that it's unlikely to be
+// returned by failing code.
+#define DEATH_SUCCESS_CODE 86
+#define EXPECT_NO_DEATH(code) EXPECT_EXIT({code; std::quick_exit(DEATH_SUCCESS_CODE);}, ::testing::ExitedWithCode(DEATH_SUCCESS_CODE), "")
+
+TEST_F(AulDeathTest, NestedFunctions)
+{
+	// Ensures the engine does not crash when a function is declared
+	// inside a proplist inside a function.
+	EXPECT_NO_DEATH(RunCode("local a = {b = func () {} };"));
+}