fix mac compile

Author: jacquesqiao

paddle/fluid/framework/details/var_handle.h

@@ -22,7 +22,7 @@
 namespace paddle {
 namespace framework {
 namespace details {
-struct OpHandleBase;
+class OpHandleBase;
 
 // VarHandleBase is the var node in the dependency graph.
 // A variable can only be generated by a single operator. i.e.

paddle/fluid/framework/parallel_executor.cc

@@ -13,9 +13,11 @@ See the License for the specific language governing permissions and
 limitations under the License. */
 
 #include "paddle/fluid/framework/parallel_executor.h"
+
 #include <string>
+#include <vector>
 
-#include "ThreadPool.h"
+#include "paddle/fluid/framework/threadpool.h"
 
 #ifdef PADDLE_WITH_CUDA
 #include "paddle/fluid/platform/nccl_helper.h"