Reorder includes. (#5749)

* Reorder includes.

* R.

src/predictor/cpu_predictor.cc

@@ -1,13 +1,13 @@
 /*!
  * Copyright by Contributors 2017-2020
  */
-#include <dmlc/omp.h>
-#include <dmlc/any.h>
-
 #include <cstddef>
 #include <limits>
 #include <mutex>
 
+#include <dmlc/omp.h>
+#include <dmlc/any.h>
+
 #include "xgboost/base.h"
 #include "xgboost/data.h"
 #include "xgboost/predictor.h"

src/predictor/gpu_predictor.cu

@@ -1,11 +1,12 @@
 /*!
  * Copyright 2017-2020 by Contributors
  */
+#include <memory>
+
 #include <thrust/copy.h>
 #include <thrust/device_ptr.h>
 #include <thrust/device_vector.h>
 #include <thrust/fill.h>
-#include <memory>
 
 #include "xgboost/data.h"
 #include "xgboost/predictor.h"

src/predictor/predictor.cc

@@ -1,9 +1,9 @@
 /*!
  * Copyright 2017-2020 by Contributors
  */
-#include <dmlc/registry.h>
 #include <mutex>
 
+#include <dmlc/registry.h>
 #include "xgboost/predictor.h"
 #include "xgboost/data.h"
 #include "xgboost/generic_parameters.h"