nlio has broken doxygen comments

[bzbarsky-apple]

Problem

Various nlio headers use [inout] instead of [in,out], which is not valid doxygen and triggers warnings on Darwin.

Proposed Solution

Figure out a way to include nlio headers as -isystem on Darwin.

Then turn on -Wdocumentation in Darwin CI.

[bzbarsky-apple]

@woody-apple

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This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs.

[stale[bot]]

This stale issue has been automatically closed. Thank you for your contributions.

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs.