linux(4): Deduplicate unimpl/dummy syscall handlers

[cem]

Summary

No functional change.

Test Plan

Tinderbox amd64 arm64 i386 passes.

[trasz]

I like it. Some of the per-architecture DUMMY() should probably get moved to the MI file too - statx for example - but that's better done later on.

[cem]

In D27099#604907, @trasz wrote:

I like it. Some of the per-architecture DUMMY() should probably get moved to the MI file too - statx for example - but that's better done later on.

Thanks! Yeah, I wasn't sure to what extent each of the syscalls.master files was accurate, but that can be updated relatively easily after this big change.

[emaste]

Thanks. I didn't check each individual entry but am very happy to see this.

[emaste]

All of the linux 4.X+ entries likely belong in the common file but agreed that can be a subsequent change

sys/arm64/linux/linux_dummy_machdep.c

4 ↗

(On Diff #79198)

This is probably not correct for arm64 now

[cem]

Thanks!

sys/arm64/linux/linux_dummy_machdep.c

4 ↗

(On Diff #79198)

Just keeping the existing copyright header (this is an svn mv from linux_dummy.c) for now: https://github.com/freebsd/freebsd/blob/master/sys/arm64/linux/linux_dummy.c#L4

[emaste]

sys/arm64/linux/linux_dummy_machdep.c

4 ↗

(On Diff #79198)

Right - I copied that statement when I copied amd64's dummy file to arm64, but everything that was copied has now been moved to the common file, so all that's left here now is what I added and your comment, which is probably the most copyrightable piece :)

Anyway doesn't really matter.