[INFRA] Import NVIDIA/CCCL upstream as optimization reference library

CCCL (CUDA C++ Core Libraries) provides:
- CUB: device/block/warp-level GPU primitives (reduce, scan, sort, topk)
- Thrust: high-level parallel algorithms (transform_reduce, sort, scan)
- libcudacxx: CUDA C++ standard library (atomics, barriers, memory)
- cudax: experimental features (memory resources, allocators)
- Tuning policies: per-SM hardware-specific algorithm parameters

Competition optimization vectors mapped to CCCL:
- Output TPS (83% weight): warp_reduce, block_reduce, device_topk
- Input TPS (14% weight): device_scan, block_load, prefetch
- Cache TPS (3% weight): prefix caching strategy patterns
- Memory (0.9 util): pooled/cached/buddy allocators

Source: https://github.com/NVIDIA/cccl (shallow clone, HEAD only)
License: Apache-2.0

cccl_upstream/thrust/thrust/detail/shuffle.inl

@@ -0,0 +1,73 @@
+// SPDX-FileCopyrightText: Copyright (c) 2008-2020, NVIDIA Corporation. All rights reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+#pragma once
+
+#include <thrust/detail/config.h>
+
+#if defined(_CCCL_IMPLICIT_SYSTEM_HEADER_GCC)
+#  pragma GCC system_header
+#elif defined(_CCCL_IMPLICIT_SYSTEM_HEADER_CLANG)
+#  pragma clang system_header
+#elif defined(_CCCL_IMPLICIT_SYSTEM_HEADER_MSVC)
+#  pragma system_header
+#endif // no system header
+#include <thrust/iterator/iterator_traits.h>
+#include <thrust/shuffle.h>
+#include <thrust/system/detail/generic/select_system.h>
+#include <thrust/system/detail/generic/shuffle.h>
+
+THRUST_NAMESPACE_BEGIN
+
+_CCCL_EXEC_CHECK_DISABLE
+template <typename DerivedPolicy, typename RandomIterator, typename URBG>
+_CCCL_HOST_DEVICE void shuffle(
+  const thrust::detail::execution_policy_base<DerivedPolicy>& exec, RandomIterator first, RandomIterator last, URBG&& g)
+{
+  _CCCL_NVTX_RANGE_SCOPE("thrust::shuffle");
+  using thrust::system::detail::generic::shuffle;
+  return shuffle(thrust::detail::derived_cast(thrust::detail::strip_const(exec)), first, last, g);
+}
+
+template <typename RandomIterator, typename URBG>
+_CCCL_HOST_DEVICE void shuffle(RandomIterator first, RandomIterator last, URBG&& g)
+{
+  _CCCL_NVTX_RANGE_SCOPE("thrust::shuffle");
+  using thrust::system::detail::generic::select_system;
+
+  using System = typename thrust::iterator_system<RandomIterator>::type;
+  System system;
+
+  return thrust::shuffle(select_system(system), first, last, g);
+}
+
+_CCCL_EXEC_CHECK_DISABLE
+template <typename DerivedPolicy, typename RandomIterator, typename OutputIterator, typename URBG>
+_CCCL_HOST_DEVICE void shuffle_copy(
+  const thrust::detail::execution_policy_base<DerivedPolicy>& exec,
+  RandomIterator first,
+  RandomIterator last,
+  OutputIterator result,
+  URBG&& g)
+{
+  _CCCL_NVTX_RANGE_SCOPE("thrust::shuffle_copy");
+  using thrust::system::detail::generic::shuffle_copy;
+  return shuffle_copy(thrust::detail::derived_cast(thrust::detail::strip_const(exec)), first, last, result, g);
+}
+
+template <typename RandomIterator, typename OutputIterator, typename URBG>
+_CCCL_HOST_DEVICE void shuffle_copy(RandomIterator first, RandomIterator last, OutputIterator result, URBG&& g)
+{
+  _CCCL_NVTX_RANGE_SCOPE("thrust::shuffle_copy");
+  using thrust::system::detail::generic::select_system;
+
+  using System1 = typename thrust::iterator_system<RandomIterator>::type;
+  using System2 = typename thrust::iterator_system<OutputIterator>::type;
+
+  System1 system1;
+  System2 system2;
+
+  return thrust::shuffle_copy(select_system(system1, system2), first, last, result, g);
+}
+
+THRUST_NAMESPACE_END