util: add pointer utils, use to constrain fs pointers

libraries/libstratosphere/include/stratosphere/fs/fs_filesystem.hpp

@@ -20,7 +20,7 @@ namespace ams::fs {
 
     namespace fsa {
 
-        class IFile;
+        class IFileSystem;
 
     }
 

libraries/libstratosphere/include/stratosphere/fs/fs_istorage.hpp

@@ -110,4 +110,7 @@ namespace ams::fs {
             }
     };
 
+    template<typename T>
+    concept PointerToStorage = ::ams::util::RawOrSmartPointerTo<T, ::ams::fs::IStorage>;
+
 }

libraries/libstratosphere/include/stratosphere/fs/fsa/fs_ifilesystem.hpp

@@ -181,4 +181,7 @@ namespace ams::fs::fsa {
             }
     };
 
+    template<typename T>
+    concept PointerToFileSystem = ::ams::util::RawOrSmartPointerTo<T, ::ams::fs::fsa::IFileSystem>;
+
 }