model_test add host place (#2109)

lite/api/model_test.cc

@@ -37,6 +37,7 @@ void OutputOptModel(const std::string& load_model_dir,
   config.set_valid_places({
       Place{TARGET(kX86), PRECISION(kFloat)},
       Place{TARGET(kARM), PRECISION(kFloat)},
+      Place{TARGET(kHost), PRECISION(kFloat)},
   });
   auto predictor = lite_api::CreatePaddlePredictor(config);
 

lite/core/mir/fusion/conv_elementwise_fuser.cc

@@ -27,8 +27,10 @@ void ConvElementwiseFuser::BuildPattern() {
       VarNode("input")->assert_is_op_input(conv_type_, "Input")->AsInput();
   auto* filter =
       VarNode("filter")->assert_is_op_input(conv_type_, "Filter")->AsInput();
-  auto* bias =
-      VarNode("bias")->assert_is_op_input("elementwise_add", "Y")->AsInput();
+  auto* bias = VarNode("bias")
+                   ->assert_is_op_input("elementwise_add", "Y")
+                   ->AsInput()
+                   ->assert_is_persistable_var();
 
   // create op nodes
   auto* conv2d =