Add test for defaultable lambda with static variable

Author: lucic71

tests/unit/lambda_static_local.cpp

@@ -1,3 +1,4 @@
+// ADDITIONAL_COMPILE_FLAGS: -std=c++23
 // translation-fail
 #include <assert.h>
 
@@ -15,6 +16,10 @@ int main() {
   assert(copy() == 3);
   assert(next() == 4);
 
+  decltype(next) fresh;
+  assert(fresh() == 5);
+  assert(next() == 6);
+
   auto per_type = [](auto x) {
     static int calls = 0;
     calls++;