🐛 fix bug of forindex/foreach, which will cause SIGSEGV.

example:

var a=func{};
forindex(a();[0,1,2]);

nasal_parse.h

@@ -946,6 +946,7 @@ nasal_ast nasal_parse::iter_gen()
         match(tok_id);
         while(is_call(tokens[ptr].type))
             node.add(call_scalar());
+        check_memory_reachable(node);
     }
     return node;
 }