config(8): Allow multiple filenames to be specified on the same line.

[• hselasky]

Summary

Typically multiple files are configured using the exact same options.
Add support to config(8) to accept a pipe character separated list
of filenames which should have all the same options.

This significantly reduces both size and churn on the kernel config
files.

Example:
dev/foo/foo.c | \
dev/foo/goo.c optional xxx

MFC after: 1 week
Sponsored by: NVIDIA Networking

[manu]

I think it's very confusing, the pipe is already used for different sets of options.
The resulting files in D33224 are really horrible to read.

[imp]

In D33223#751011, @manu wrote:

I think it's very confusing, the pipe is already used for different sets of options.
The resulting files in D33224 are really horrible to read.

And we can turn file into file list w/o the pipes.

But honestly, I'd rather we hack config(8) to generate some standardish thing that libucl can cope with and then rewrite off of that base. The efforts likely would be smaller or about the same as these cleanups and we'd be miles ahead at the end.