include: Delete stale symlinks using find(1) instead of a shell loop.

[arichardson]

Summary

This reduces the number of processes spawned during make includes from 2536
to 2442.

[bdrewery]

include/Makefile

277–281

There's a similar check in copies. Both are dealing with a symlinked dir (here) or header (there) switching to a file by choice of committers. If INCSLINKS or the mtree change we could get into trouble. Or someone might be switching from make symlinks to default make copies on the destdir. I think we need to keep this as a seatbelt for _any_ incremental build in WORLDTMP, or install to DESTDIR.

It could probably be more efficient with a find but getting all the arguments to there without going over the command line arg max is tricky.

[bdrewery]

include/Makefile

277–281

like find ${LDIRS} ${LSUBDIRS} machine ${_MARCHS} crypto -maxdepth 1 -mindepth 1 -type l -delete (-depth 1 is slower for some reason). I was wanting to give an xargs example but bmake just passes it all to sh -c anyway so it doesn't help avoid the problem.

[arichardson]

include/Makefile

277–281

Yes, much better! Included in updated version. However, in this case it needs to be maxdepth 0, and 1 below.

[arichardson]

Use find(1)

[arichardson]

include/Makefile

288

-print is not necessary here, but I think it could be helpful since it shows the files that have been deleted.

[arichardson]

ping?

[jhb]

I think this looks ok.