MFC r339962 into stable/12

[0mp]

MFC r339962:

ps(1): Pet mandoc and igor

- Use Xr to reference other manual pages.
- Reference execve(2) instead of exec(2) as exec(2) does not exist.
- Remove the deprecated "Tn" macro.
- Improve the formatting of the etime description.

Reviewed by:	bcr
Approved by:	krion (mentor, implicit), mat (mentor, implicit)
Differential Revision:	https://reviews.freebsd.org/D17780

Approved by:	bcr (mentor)
Differential Revision:	https://reviews.freebsd.org/D24047

[bcr]

No bump of .Dd? Ah well, you can do that in a separate commit after.

[0mp]

In D24047#528732, @bcr wrote:

No bump of .Dd?

Do we bump Dd when MFC'ing?

Ah well, you can do that in a separate commit after.

A commit bumping Dd must go directly into a stable branch, right?

[bcr]

Didn't the original commit to HEAD bump the .Dd? You need to make the change there first, not in stable.

[0mp]

In D24047#528749, @bcr wrote:

Didn't the original commit to HEAD bump the .Dd? You need to make the change there first, not in stable.

I just checked and there's another commit I have pending for MFC that bumps it so everything is fine. ;)

[bcr]

OK, go ahead then!

[bcr]

Officially accept it, Phabricator won't let me in my last comment.