ARROW-18406: [C++] Can't build Arrow with Substrait on Ubuntu 20.04

[westonpace]

No description provided.

[github-actions]

https://issues.apache.org/jira/browse/ARROW-18406

[github-actions]

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

[westonpace]

This is something I think we will eventually want a good way to regress. Perhaps a nightly job for Ubuntu 20.04 that uses the system libraries instead of conda? I say this because I think this is the second or third time a regression of this style has been introduced.

[westonpace]

Also, to be clear, the change here was not actually a code change. We always had has_enum_(). However, in older versions of protoc it is only valid to call has_xyz() if xyz is a message. If xyz is an enum or other simple type (in this case a string) then you have to instead check against the default value for that type (because protobuf, in these cases, does not distinguish between the two)

So when we got the new Substrait version it changed the field enum from a message to a string. Admittedly, this kind of backwards incompatible change should be quite rare.

[paleolimbot]

I did a local checkout of this and can confirm that it builds with system protoc (at least on my own Ubuntu 20.04 box!).

[ursabot]

Benchmark runs are scheduled for baseline = c0b311e and contender = 409a95d. 409a95d 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
[Finished ⬇️0.34% ⬆️0.44%] test-mac-arm
[Finished ⬇️0.0% ⬆️0.0%] ursa-i9-9960x
[Finished ⬇️0.28% ⬆️0.7%] ursa-thinkcentre-m75q
Buildkite builds:
[Finished] 409a95dd ec2-t3-xlarge-us-east-2
[Finished] 409a95dd test-mac-arm
[Finished] 409a95dd ursa-i9-9960x
[Finished] 409a95dd ursa-thinkcentre-m75q
[Finished] c0b311ee ec2-t3-xlarge-us-east-2
[Finished] c0b311ee test-mac-arm
[Finished] c0b311ee ursa-i9-9960x
[Finished] c0b311ee 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