Compiler didn't check foreach over flexible array member, and folding a flexible array member was allowed #2164.

test/test_suite/generic/generic_self_ref.c3

@@ -10,7 +10,7 @@ struct Widget
 	List {any} children;
 }
 
-fn void Widget{Label}.draw(Widget* self) // #error: This identifier is recursively using gui::widget
+fn void Widget{Label}.draw(Widget* self) // #error: The same method is generated by multiple instances
 {
 	io::printfn("Hello Label");
 }

test/test_suite/statements/foreach_fails.c3

@@ -0,0 +1,15 @@
+struct Abc
+{
+  int a;
+  int[*] b;
+}
+fn void test()
+{
+	Abc y = {};
+	foreach (x : y.b) {} // #error: It is not possible to enumerate over a flexible
+}
+fn int main()
+{
+  foreach (x : (Abc){}.b) {} // #error: it's a flexible array member
+  return 0;
+}