GH-43507: [C++] Use ViewOrCopyTo instead of CopyTo when pretty printing non-CPU data

[jorisvandenbossche]

Rationale for this change

When ensuring the data we are pretty-printing is on the CPU, we can use ViewOrCopyTo instead of CopyTo, in case the data can be viewed as CPU data without a copy.

Are these changes tested?

Yes (I added a test that uses CUDA host memory, which should be a case where it can be viewed and doesn't need to be copied, but of course the test it not actually ensuring we avoid the copy, just that the printing works)

Are there any user-facing changes?

No

• GitHub Issue: [C++] Use ViewOrCopyTo instead of CopyTo when pretty printing non-CPU data #43507

[jorisvandenbossche]

@github-actions crossbow submit test-cuda-cpp test-cuda-python

[github-actions]

Revision: 1760a86

Submitted crossbow builds: ursacomputing/crossbow @ actions-ac5d396a7c

Task	Status
test-cuda-cpp
test-cuda-python

[kou]

+1

[conbench-apache-arrow]

After merging your PR, Conbench analyzed the 4 benchmarking runs that have been run so far on merge-commit b35e7dd.

There were no benchmark performance regressions. 🎉

The full Conbench report has more details. It also includes information about 6 possible false positives for unstable benchmarks that are known to sometimes produce them.