Prevent users from building obviously defective Linuxulator modules.

[dchagin]

Summary

Linuxulator depends on a fundamental kernel settings such as SMP. Many
of them listed in opt_global.h which is not generated while building
modules outside of a kernel and such modules never match real cofigured
kernel.

So, we should prevent our users from building obviously defective modules.

Therefore, I propose to remove the root cause of the building of modules
outside of a kernel - the possibility of building modules with DEBUG or KTR
flags. And remove all of DEBUG printfs as it is incomplete and in threaded
programms not informative, also a half of system call does not have DEBUG
printf. For debuging Linux programms we have dtrace, ktr and ktrace ability.

PR: 222861

[trasz]

Have you considered splitting it into two: one for getting rid of DEBUG, and one for preventing out of tree builds? The former looks fine, but I don’t understand the build system well enough wrt the latter.

[dchagin]

split to get rid of DEBUG and warn

[dchagin]

wrong phab diff, sorry

[trasz]

The title and description don't match the patch, but apart from that - looks good!