Merge branch 'gru_operator' into lstm_operator

src/rewrite_rnn.cpp

@@ -477,9 +477,10 @@ std::vector<instruction_ref> rewrite_rnn::gru_cell(bool is_forward,
     auto bias = inputs.at(3);
     auto ih   = inputs.at(4);
 
-    instruction_ref hidden_states = prog.end(), last_output;
-    long seq_len                  = static_cast<long>(seq->get_shape().lens()[0]);
-    long hs                       = static_cast<long>(r->get_shape().lens()[2]);
+    instruction_ref hidden_states = prog.end();
+    instruction_ref last_output{};
+    long seq_len = static_cast<long>(seq->get_shape().lens()[0]);
+    long hs      = static_cast<long>(r->get_shape().lens()[2]);
 
     migraphx::shape s(seq->get_shape().type(),
                       {seq->get_shape().lens()[1], static_cast<std::size_t>(hs)});