ARROW-17844: [C++] Remove atomic shared_ptr compatibility functions

[pitrou]

No description provided.

[pitrou]

Revision: d6b8a00

Submitted crossbow builds: ursacomputing/crossbow @ atomic-shared-ptr-0

Task	Status
test-alpine-linux-cpp
test-build-cpp-fuzz
test-conda-cpp
test-conda-cpp-valgrind
test-debian-10-cpp-amd64
test-debian-10-cpp-i386
test-debian-11-cpp-amd64
test-debian-11-cpp-i386
test-fedora-35-cpp
test-ubuntu-18.04-cpp
test-ubuntu-18.04-cpp-release
test-ubuntu-18.04-cpp-static
test-ubuntu-20.04-cpp
test-ubuntu-20.04-cpp-17
test-ubuntu-20.04-cpp-bundled
test-ubuntu-20.04-cpp-thread-sanitizer
test-ubuntu-22.04-cpp

[westonpace]

Good catch, thanks.

[westonpace]

Technically I suppose we should add #include <atomic> for IWYU but it is probably transitively included by most standard includes.

[pitrou]

You're right, let's do it.

[pitrou]

CI looks green on my fork (apart from a seemingly unrelated R failure), will merge.

[ursabot]

Benchmark runs are scheduled for baseline = 9b4a181 and contender = 5b29dd0. 5b29dd0 is a master commit associated with this PR. Results will be available as each benchmark for each run completes.
Conbench compare runs links:
[Finished ⬇️0.0% ⬆️0.0%] ec2-t3-xlarge-us-east-2
[Failed ⬇️0.48% ⬆️0.0%] test-mac-arm
[Failed ⬇️0.0% ⬆️0.0%] ursa-i9-9960x
[Finished ⬇️0.43% ⬆️0.0%] ursa-thinkcentre-m75q
Buildkite builds:
[Finished] 5b29dd06 ec2-t3-xlarge-us-east-2
[Finished] 5b29dd06 test-mac-arm
[Failed] 5b29dd06 ursa-i9-9960x
[Finished] 5b29dd06 ursa-thinkcentre-m75q
[Finished] 9b4a181d ec2-t3-xlarge-us-east-2
[Failed] 9b4a181d test-mac-arm
[Failed] 9b4a181d ursa-i9-9960x
[Finished] 9b4a181d ursa-thinkcentre-m75q
Supported benchmarks:
ec2-t3-xlarge-us-east-2: Supported benchmark langs: Python, R. Runs only benchmarks with cloud = True
test-mac-arm: Supported benchmark langs: C++, Python, R
ursa-i9-9960x: Supported benchmark langs: Python, R, JavaScript
ursa-thinkcentre-m75q: Supported benchmark langs: C++, Java