LibCore: Add DirIterator::next_full_path()

Author: https://github.com/shannonbooth
Commit: 42399167b3
Pull-request: https://github.com/SerenityOS/serenity/pull/1225

Libraries/LibCore/DirIterator.h

@@ -47,11 +47,13 @@ public:
     const char* error_string() const { return strerror(m_error); }
     bool has_next();
     String next_path();
+    String next_full_path();
 
 private:
     DIR* m_dir = nullptr;
     int m_error = 0;
     String m_next;
+    String m_path;
     int m_flags;
 
     bool advance_next();