ARROW-17875: [C++] Remove assorted pre-C++17 compatibility measures

[pitrou]

No description provided.

[pitrou]

Revision: 7e3a408

Submitted crossbow builds: ursacomputing/crossbow @ cpp17-compat-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

[github-actions]

https://issues.apache.org/jira/browse/ARROW-17875

[github-actions]

⚠️ Ticket has not been started in JIRA, please click 'Start Progress'.

[ursabot]

Benchmark runs are scheduled for baseline = e42b26a and contender = 9af43f1. 9af43f1 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 ⬇️0.07% ⬆️0.2%] test-mac-arm
[Failed ⬇️0.55% ⬆️0.27%] ursa-i9-9960x
[Finished ⬇️0.21% ⬆️0.0%] ursa-thinkcentre-m75q
Buildkite builds:
[Finished] 9af43f11 ec2-t3-xlarge-us-east-2
[Failed] 9af43f11 test-mac-arm
[Failed] 9af43f11 ursa-i9-9960x
[Finished] 9af43f11 ursa-thinkcentre-m75q
[Finished] e42b26af ec2-t3-xlarge-us-east-2
[Failed] e42b26af test-mac-arm
[Failed] e42b26af ursa-i9-9960x
[Finished] e42b26af 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

[ursabot]

['Python', 'R'] benchmarks have high level of regressions.
ursa-i9-9960x