[C++][Compute] Add unary negative kernel

[asfimport]

Related to ARROW-11945. So that you can have an expression like -col. You can approximate this with doing 0 - col, but I would guess it could be done more efficiently.

cc @bkietz

Reporter: Neal Richardson / @nealrichardson
Assignee: Eduardo Ponce / @edponce

Related issues:

• [C++] Arithmetic kernels for numeric arrays (is a child of)

PRs and other links:

• GitHub Pull Request #10016
• GitHub Pull Request #10113

_{Note: This issue was originally created as ARROW-11950. Please see the migration documentation for further details.}

[asfimport]

Ben Kietzman / @bkietz:
Issue resolved by pull request 10113
#10113