chore: import upstream snapshot with attribution

paddle/phi/api/include/compat/ATen/DeviceGuard.h

@@ -0,0 +1,35 @@
+// Copyright (c) 2025 PaddlePaddle Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#pragma once
+
+#include <ATen/Tensor.h>
+#include <c10/core/ScalarType.h>
+#include <c10/util/Optional.h>
+
+namespace at {
+
+inline std::optional<Device> device_of(const Tensor& t) {
+  if (t.defined()) {
+    return t.device();
+  } else {
+    return std::nullopt;
+  }
+}
+
+inline std::optional<Device> device_of(const std::optional<Tensor>& t) {
+  return t.has_value() ? device_of(t.value()) : std::nullopt;
+}
+
+}  // namespace at