-Add visible IO errors when closing a file fails due to it being locked (most likely on windows), closes #4760

drivers/windows/file_access_windows.cpp

@@ -131,6 +131,10 @@ void FileAccessWindows::close() {
 			//atomic replace for existing file
 			rename_error = !ReplaceFileW(save_path.c_str(), (save_path+".tmp").c_str(), NULL, 2|4, NULL, NULL);
 		}
+		if (rename_error && close_fail_notify) {
+			close_fail_notify(save_path);
+		}
+
 		save_path="";
 		ERR_FAIL_COND( rename_error );
 	}