Saveload: Add NamedSaveLoad to saveload_common.h

src/sl/saveload_common.h

@@ -13,9 +13,11 @@
 #include "../strings_type.h"
 
 struct SaveLoad;
+struct NamedSaveLoad;
 
 /** A table of SaveLoad entries. */
 using SaveLoadTable = std::span<const SaveLoad>;
+using NamedSaveLoadTable = std::span<const NamedSaveLoad>;
 
 namespace upstream_sl {
 	struct SaveLoad;

src/sl/saveload_types.h

@@ -162,6 +162,5 @@ inline constexpr NamedSaveLoad NSLT(const char *name, SaveLoad save_load)
 {
 	return { name, save_load, NSLF_TABLE_ONLY };
 }
-using NamedSaveLoadTable = std::span<const NamedSaveLoad>;
 
 #endif /* SL_SAVELOAD_TYPES_H */