[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/testing/tbb_nvcc_preinclude.h

@@ -0,0 +1,25 @@
+// This file is intended to be force included by the compiler (using -include=tbb_preinclude.h). It's purpose is to fix
+// unrecognized builtins by cudafe++ that are used in <immintrin.h>. We simply forward declare them in global namespace.
+
+#if defined(_IMMINTRIN_H_INCLUDED)
+#  error "This file must be included before <immintrin.h>"
+#endif // _IMMINTRIN_H_INCLUDED
+
+#if defined(__NVCC__) && defined(__CUDACC__)
+// Forward declare builtins used by gcc 12. Clang and nvc++ define __GNUC__, too, so we need to explicitly leave them
+// out.
+#  if defined(__GNUC__) && !defined(__clang__) && !defined(__NVCOMPILER)
+#    if __CUDACC_VER_MAJOR__ == 12 && __CUDACC_VER_MINOR__ == 0 && __GNUC__ == 12
+void __builtin_ia32_ldtilecfg(const void*);
+void __builtin_ia32_sttilecfg(void*);
+#    endif // __CUDACC_VER_MAJOR__ == 12 && __CUDACC_VER_MINOR__ == 0 && __GNUC__ == 12
+#  endif // __GNUC__ && !__clang__ && !__NVCOMPILER
+
+// cudafe++ has problems with many builtins used in <avx512fp16intrin.h> and <avx512vlfp16intrin.h> when compiling with
+// nvc++ as the host compiler. Since those headers are not used by thrust nor tbb, we can prevent their inclusion by
+// defining their include guard macros.
+#  if defined(__NVCOMPILER)
+#    define __AVX512FP16INTRIN_H
+#    define __AVX512VLFP16INTRIN_H
+#  endif // __NVCOMPILER
+#endif // __NVCC__ && __CUDACC__