[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/cmake/ThrustBuildCompilerTargets.cmake

@@ -0,0 +1,38 @@
+# This file defines the `thrust_build_compiler_targets()` function, which
+# creates the following interface targets:
+#
+# thrust.compiler_interface
+# Provides compiler settings for all thrust tests, examples, etc. This should not be used
+# directly, as it is linked to by all thrust configuration targets in THRUST_TARGETS.
+
+function(thrust_build_compiler_targets)
+  set(cuda_compile_options)
+  set(cxx_compile_options)
+  set(cxx_compile_definitions)
+
+  if ("MSVC" STREQUAL "${CMAKE_CXX_COMPILER_ID}")
+    # Disabled loss-of-data conversion warnings.
+    # TODO Re-enable.
+    append_option_if_available("/wd4244" cxx_compile_options)
+
+    # Disable warning about applying unary operator- to unsigned type.
+    # TODO Re-enable.
+    append_option_if_available("/wd4146" cxx_compile_options)
+  endif()
+
+  cccl_build_compiler_interface(
+    thrust.compiler_flags
+    "${cuda_compile_options}"
+    "${cxx_compile_options}"
+    "${cxx_compile_definitions}"
+  )
+
+  add_library(thrust.compiler_interface INTERFACE)
+  target_link_libraries(
+    thrust.compiler_interface
+    INTERFACE
+      # order matters here, we need the project options to override the cccl options.
+      cccl.compiler_interface
+      thrust.compiler_flags
+  )
+endfunction()