Add boost hash_combine function

Author: ZzEeKkAa

LICENSES.third-party

@@ -0,0 +1,30 @@
+The numba-dpex source tree includes vendored libraries governed by the following
+licenses.
+
+
+boost hash.hpp header
+---------------------
+
+Boost Software License - Version 1.0 - August 17th, 2003
+
+Permission is hereby granted, free of charge, to any person or organization
+obtaining a copy of the software and accompanying documentation covered by
+this license (the "Software") to use, reproduce, display, distribute,
+execute, and transmit the Software, and to prepare derivative works of the
+Software, and to permit third-parties to whom the Software is furnished to
+do so, all subject to the following:
+
+The copyright notices in the Software and this entire statement, including
+the above license grant, this restriction and the following disclaimer,
+must be included in all copies of the Software, in whole or in part, and
+all derivative works of the Software, unless such copies or derivative
+works are solely in the form of machine-executable object code generated by
+a source language processor.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
+SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
+FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
+ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.

numba_dpex/core/runtime/experimental/tools/boost_hash.hpp

@@ -0,0 +1,38 @@
+// Copyright 2005-2014 Daniel James.
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+//  Based on Peter Dimov's proposal
+//  http://www.open-std.org/JTC1/SC22/WG21/docs/papers/2005/n1756.pdf
+//  issue 6.18.
+//
+//  This also contains public domain code from MurmurHash. From the
+//  MurmurHash header:
+
+// MurmurHash3 was written by Austin Appleby, and is placed in the public
+// domain. The author hereby disclaims copyright to this source code.
+
+// 2023 Intel Corporation
+// Copied hash_combine and hash_combine_impl from boost
+// (https://www.boost.org/doc/libs/1_76_0/boost/container_hash/hash.hpp) and
+// changed hash_combine to use std::hash<T> instead of boost::hash<T>.
+
+#include <functional>
+
+namespace boost
+{
+namespace hash_detail
+{
+template <typename SizeT>
+inline void hash_combine_impl(SizeT &seed, SizeT value)
+{
+    seed ^= value + 0x9e3779b9 + (seed << 6) + (seed >> 2);
+}
+} // namespace hash_detail
+
+template <class T> inline void hash_combine(std::size_t &seed, T const &v)
+{
+    std::hash<T> hasher;
+    return boost::hash_detail::hash_combine_impl(seed, hasher(v));
+}
+} // namespace boost