Kernel: Fix directory permissions

We did not care about X bit in directories and instead used only the
R bit for search/read.

kernel/include/kernel/OpenFileDescriptorSet.h

@@ -34,6 +34,8 @@ namespace Kernel
 		BAN::ErrorOr<off_t> tell(int) const;
 
 		BAN::ErrorOr<void> fstat(int fd, struct stat*) const;
+		BAN::ErrorOr<void> fstatat(int fd, BAN::StringView path, struct stat* buf, int flag);
+		BAN::ErrorOr<void> stat(BAN::StringView absolute_path, struct stat* buf, int flag);
 
 		BAN::ErrorOr<void> close(int);
 		void close_all();