sysupdater: don't do unnecessary work when parsing update

stratosphere/ams_mitm/source/sysupdater/sysupdater_fs_utils.hpp

@@ -18,6 +18,16 @@
 
 namespace ams::mitm::sysupdater {
 
+    class PathView {
+        private:
+            std::string_view path; /* Nintendo uses util::string_view here. */
+        public:
+            PathView(std::string_view p) : path(p) { /* ...*/ }
+            bool HasPrefix(std::string_view prefix) const;
+            bool HasSuffix(std::string_view suffix) const;
+            std::string_view GetFileName() const;
+    };
+
     Result MountSdCardContentMeta(const char *mount_name, const char *path);
 
 }