[C++] Add RE2 to minimal build example

[asfimport]

We require RE2 with ARROW_COMPUTE by default.

See also: ARROW-10541

Reporter: Kouhei Sutou / @kou
Assignee: Kouhei Sutou / @kou

PRs and other links:

• GitHub Pull Request #8786

_{Note: This issue was originally created as ARROW-10751. Please see the migration documentation for further details.}

[asfimport]

Antoine Pitrou / @pitrou:
Hmm... well, the point of the minimal build example is to show the most minimal build.

[asfimport]

Kouhei Sutou / @kou:
cpp/examples/minimal_build/run.sh shows the minimal build options case with a minimal project.
But cpp/examples/minimal_build/run_static.sh shows many build options with system dependencies works well with a minimal project.

See also: https://github.com/apache/arrow/blob/master/cpp/examples/minimal_build/README.md

This is for the latter.
Should we change directory name for the latter?

[asfimport]

Antoine Pitrou / @pitrou:
cc @wesm

[asfimport]

Antoine Pitrou / @pitrou:
Ok, I hadn't noticed that run_static.sh already had other dependencies. Then it sounds ok to me.

[asfimport]

Antoine Pitrou / @pitrou:
Issue resolved by pull request 8786
#8786