add cudax::distribute<threadsPrBlock>(numElements)

[ericniebler]

… as a way to evenly distribute elements over thread blocks.

Description

cudax::distribute<threadsPrBlock>(numElements) is a shortcut notation for:

int blocksPerGrid = (numElements + threadsPrBlock - 1) / threadsPrBlock;
return cudax::make_hierarchy(cudax::grid_dims(blocksPerGrid), cudax::block_dims<threadsPrBlock>());

This will be used in the compute all hands presentation about cudax

[github-actions]

🟩 CI finished in 2h 09m: Pass: 100%/56 | Total: 2h 46m | Avg: 2m 58s | Max: 11m 03s | Hits: 51%/94

• 🟩 cudax: Pass: 100%/55 | Total: 2h 35m | Avg: 2m 49s | Max: 8m 34s | Hits: 51%/94

  🟩 cpu
    🟩 amd64              Pass: 100%/51  | Total:  2h 24m | Avg:  2m 49s | Max:  8m 34s | Hits:  51%/94    
    🟩 arm64              Pass: 100%/4   | Total: 11m 40s | Avg:  2m 55s | Max:  3m 26s
  🟩 ctk
    🟩 12.0               Pass: 100%/23  | Total:  1h 04m | Avg:  2m 48s | Max:  8m 34s | Hits:  51%/47    
    🟩 12.5               Pass: 100%/32  | Total:  1h 31m | Avg:  2m 50s | Max:  8m 29s | Hits:  51%/47    
  🟩 cudacxx
    🟩 nvcc12.0           Pass: 100%/23  | Total:  1h 04m | Avg:  2m 48s | Max:  8m 34s | Hits:  51%/47    
    🟩 nvcc12.5           Pass: 100%/32  | Total:  1h 31m | Avg:  2m 50s | Max:  8m 29s | Hits:  51%/47    
  🟩 cudacxx_family
    🟩 nvcc               Pass: 100%/55  | Total:  2h 35m | Avg:  2m 49s | Max:  8m 34s | Hits:  51%/94    
  🟩 cxx
    🟩 Clang9             Pass: 100%/2   | Total:  4m 41s | Avg:  2m 20s | Max:  2m 31s
    🟩 Clang10            Pass: 100%/2   | Total:  4m 46s | Avg:  2m 23s | Max:  2m 30s
    🟩 Clang11            Pass: 100%/4   | Total: 10m 08s | Avg:  2m 32s | Max:  2m 59s
    🟩 Clang12            Pass: 100%/4   | Total:  9m 15s | Avg:  2m 18s | Max:  2m 32s
    🟩 Clang13            Pass: 100%/4   | Total:  9m 29s | Avg:  2m 22s | Max:  2m 27s
    🟩 Clang14            Pass: 100%/6   | Total: 17m 03s | Avg:  2m 50s | Max:  3m 51s
    🟩 Clang15            Pass: 100%/2   | Total:  4m 38s | Avg:  2m 19s | Max:  2m 19s
    🟩 Clang16            Pass: 100%/6   | Total: 18m 46s | Avg:  3m 07s | Max:  4m 16s
    🟩 GCC9               Pass: 100%/2   | Total:  4m 54s | Avg:  2m 27s | Max:  2m 50s
    🟩 GCC10              Pass: 100%/4   | Total:  9m 21s | Avg:  2m 20s | Max:  2m 26s
    🟩 GCC11              Pass: 100%/4   | Total:  9m 14s | Avg:  2m 18s | Max:  2m 37s
    🟩 GCC12              Pass: 100%/12  | Total: 33m 28s | Avg:  2m 47s | Max:  3m 40s
    🟩 Intel2023.2.0      Pass: 100%/1   | Total:  2m 55s | Avg:  2m 55s | Max:  2m 55s
    🟩 MSVC14.36          Pass: 100%/1   | Total:  8m 34s | Avg:  8m 34s | Max:  8m 34s | Hits:  51%/47    
    🟩 MSVC14.39          Pass: 100%/1   | Total:  8m 29s | Avg:  8m 29s | Max:  8m 29s | Hits:  51%/47    
  🟩 cxx_family
    🟩 Clang              Pass: 100%/30  | Total:  1h 18m | Avg:  2m 37s | Max:  4m 16s
    🟩 GCC                Pass: 100%/22  | Total: 56m 57s | Avg:  2m 35s | Max:  3m 40s
    🟩 Intel              Pass: 100%/1   | Total:  2m 55s | Avg:  2m 55s | Max:  2m 55s
    🟩 MSVC               Pass: 100%/2   | Total: 17m 03s | Avg:  8m 31s | Max:  8m 34s | Hits:  51%/94    
  🟩 gpu
    🟩 v100               Pass: 100%/55  | Total:  2h 35m | Avg:  2m 49s | Max:  8m 34s | Hits:  51%/94    
  🟩 jobs
    🟩 Build              Pass: 100%/47  | Total:  2h 06m | Avg:  2m 40s | Max:  8m 34s | Hits:  51%/94    
    🟩 Test               Pass: 100%/8   | Total: 29m 37s | Avg:  3m 42s | Max:  4m 16s
  🟩 sm
    🟩 90                 Pass: 100%/1   | Total:  1m 53s | Avg:  1m 53s | Max:  1m 53s
    🟩 90a                Pass: 100%/1   | Total:  2m 11s | Avg:  2m 11s | Max:  2m 11s
  🟩 std
    🟩 17                 Pass: 100%/31  | Total:  1h 20m | Avg:  2m 36s | Max:  4m 16s
    🟩 20                 Pass: 100%/24  | Total:  1h 15m | Avg:  3m 07s | Max:  8m 34s | Hits:  51%/94    
  

• 🟩 pycuda: Pass: 100%/1 | Total: 11m 03s | Avg: 11m 03s | Max: 11m 03s

  🟩 cpu
    🟩 amd64              Pass: 100%/1   | Total: 11m 03s | Avg: 11m 03s | Max: 11m 03s
  🟩 ctk
    🟩 12.5               Pass: 100%/1   | Total: 11m 03s | Avg: 11m 03s | Max: 11m 03s
  🟩 cudacxx
    🟩 nvcc12.5           Pass: 100%/1   | Total: 11m 03s | Avg: 11m 03s | Max: 11m 03s
  🟩 cudacxx_family
    🟩 nvcc               Pass: 100%/1   | Total: 11m 03s | Avg: 11m 03s | Max: 11m 03s
  🟩 cxx
    🟩 GCC13              Pass: 100%/1   | Total: 11m 03s | Avg: 11m 03s | Max: 11m 03s
  🟩 cxx_family
    🟩 GCC                Pass: 100%/1   | Total: 11m 03s | Avg: 11m 03s | Max: 11m 03s
  🟩 gpu
    🟩 v100               Pass: 100%/1   | Total: 11m 03s | Avg: 11m 03s | Max: 11m 03s
  🟩 jobs
    🟩 Test               Pass: 100%/1   | Total: 11m 03s | Avg: 11m 03s | Max: 11m 03s
  

👃 Inspect Changes

Modifications in project?

	Project
	CCCL Infrastructure
	libcu++
	CUB
	Thrust
+/-	CUDA Experimental
	pycuda

Modifications in project or dependencies?

	Project
	CCCL Infrastructure
	libcu++
	CUB
	Thrust
+/-	CUDA Experimental
+/-	pycuda

🏃‍ Runner counts (total jobs: 56)

#	Runner
41	linux-amd64-cpu16
9	linux-amd64-gpu-v100-latest-1
4	linux-arm64-cpu16
2	windows-amd64-cpu16