[C++] Arrow 12.0.0-1 cpp exposes internal headers

[marsupialtail]

Describe the bug, including details regarding any error messages, version, and platform.

it exposes compute/key_map.h.
However, compute/key_map.h relies on compute/util_internal.h which is not exposed.

Ubuntu

Component(s)

C++

[kou]

Oh...
This was introduced by #34518.

@LDipo Could you fix this?
(Cc: Reviewers: @icexelloss @westonpace )

We may want to add a lint check or something that detects private/internal headers includes from public headers.

[icexelloss]

Thanks @kou. Let me ping @ildipo and see if he can take a look.

[icexelloss]

@ildipo is out Today and he says he will take a look Monday

[kou]

Thanks! (And sorry for my wrong mention...)

[ildipo]

on it

[ildipo]

take