ARROW-17696: [C++] arrow-compute-asof-join-node-test inordinately slow

[rtpsw]

See https://issues.apache.org/jira/browse/ARROW-17696

[github-actions]

https://issues.apache.org/jira/browse/ARROW-17696

[pitrou]

Thanks for this @rtpsw . This will be a nice quality of life improvement for contributors.
(also might make CI slightly less laggy :-))

[ursabot]

Benchmark runs are scheduled for baseline = 58be6a3 and contender = 87d102e. 87d102e 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 ⬇️0.58% ⬆️0.03%] test-mac-arm
[Failed ⬇️0.0% ⬆️0.0%] ursa-i9-9960x
[Finished ⬇️0.28% ⬆️0.04%] ursa-thinkcentre-m75q
Buildkite builds:
[Finished] 87d102eb ec2-t3-xlarge-us-east-2
[Finished] 87d102eb test-mac-arm
[Failed] 87d102eb ursa-i9-9960x
[Finished] 87d102eb ursa-thinkcentre-m75q
[Finished] 58be6a31 ec2-t3-xlarge-us-east-2
[Failed] 58be6a31 test-mac-arm
[Failed] 58be6a31 ursa-i9-9960x
[Finished] 58be6a31 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