[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/libcudacxx/test/support/test.workarounds/c1xx_broken_za_ctor_check.pass.cpp

@@ -0,0 +1,43 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// Verify TEST_WORKAROUND_C1XX_BROKEN_ZA_CTOR_CHECK.
+
+#include <cuda/std/type_traits>
+
+#include "test_macros.h"
+#include "test_workarounds.h"
+
+struct X
+{
+  TEST_FUNC X(int) {}
+
+  X(X&&)            = default;
+  X& operator=(X&&) = default;
+
+private:
+  X(const X&)            = default;
+  X& operator=(const X&) = default;
+};
+
+TEST_FUNC void PushFront(X&&) {}
+
+template <class T = int>
+TEST_FUNC auto test(int) -> decltype(PushFront(cuda::std::declval<T>()), cuda::std::true_type{});
+TEST_FUNC auto test(long) -> cuda::std::false_type;
+
+int main(int, char**)
+{
+#if defined(TEST_WORKAROUND_C1XX_BROKEN_ZA_CTOR_CHECK)
+  static_assert(!decltype(test(0))::value);
+#else
+  static_assert(decltype(test(0))::value);
+#endif
+
+  return 0;
+}