simplify generate_tuple (#2043)

include/ck/utility/sequence.hpp

@@ -184,6 +184,21 @@ struct Sequence
     }
 };
 
+namespace impl {
+template <typename T, T... Ints>
+struct __integer_sequence;
+
+template <index_t... Ints>
+struct __integer_sequence<index_t, Ints...>
+{
+    using seq_type = Sequence<Ints...>;
+};
+} // namespace impl
+
+template <index_t N>
+using make_index_sequence =
+    typename __make_integer_seq<impl::__integer_sequence, index_t, N>::seq_type;
+
 // merge sequence
 template <typename Seq, typename... Seqs>
 struct sequence_merge