[SYCL][UR][L0 v2] Fix ur_mem_handle_t_ (#18768)

It needs to inherit from ur::handle_base<ur::level_zero::ddi_getter>

Previously, only ur_mem_buffer_t inherited from the handle_base which
happened to work in most cases as ur_mem_handle_t_ is a variant over few
different types, all inheriting from ur_mem_handle_t_.

Author: igchor

unified-runtime/source/adapters/level_zero/v2/memory.hpp

@@ -247,7 +247,7 @@ struct ur_mem_image_t : ur_object {
   ZeStruct<ze_image_desc_t> zeImageDesc;
 };
 
-struct ur_mem_handle_t_ {
+struct ur_mem_handle_t_ : ur::handle_base<ur::level_zero::ddi_getter> {
   template <typename T, typename... Args>
   static ur_mem_handle_t_ *create(Args &&...args) {
     return new ur_mem_handle_t_(std::in_place_type<T>,
@@ -293,7 +293,8 @@ struct ur_mem_handle_t_ {
 private:
   template <typename T, typename... Args>
   ur_mem_handle_t_(std::in_place_type_t<T>, Args &&...args)
-      : mem(std::in_place_type<T>, std::forward<Args>(args)...) {}
+      : ur::handle_base<ur::level_zero::ddi_getter>(),
+        mem(std::in_place_type<T>, std::forward<Args>(args)...) {}
 
   std::variant<ur_usm_handle_t, ur_integrated_buffer_handle_t,
                ur_discrete_buffer_handle_t, ur_shared_buffer_handle_t,