chore: import upstream snapshot with attribution

csrc/utils/py_ds_utils.cpp

@@ -0,0 +1,25 @@
+// Copyright (c) Microsoft Corporation.
+// SPDX-License-Identifier: Apache-2.0
+
+// DeepSpeed Team
+
+/*
+    Collection of system utilities.
+*/
+
+#include <torch/extension.h>
+#include "tensor_cast.h"
+using namespace pybind11::literals;
+
+PYBIND11_MODULE(TORCH_EXTENSION_NAME, m)
+{
+    m.def("cast_to_byte_tensor",
+          py::overload_cast<at::Tensor&>(&cast_to_byte_tensor),
+          "Cast a 1-dimensional tensor of any type to byte tensor.",
+          "src_tensor"_a);
+
+    m.def("cast_to_byte_tensor",
+          py::overload_cast<std::vector<at::Tensor>&>(&cast_to_byte_tensor),
+          "Cast a multi-dimensional tensor of any type to byte tensor.",
+          "src_tensor"_a);
+}