Heads up, changes to modules/exec/etc, note for portmasters/developers

[Andrew Doran <ad%netbsd.org@localhost>]

Hi,

I made a bunch of changes to the compat code, exec formats, NFS server, NFS
and coredumps in the kernel.

Most of the changes are mundane and are to allow them to be loaded as
modules. I have tested on i386, and done builds for i386 amd64 sparc
sparc64. I ran into a few obscure bugs along the way and it's possible that
some still lurk or that there are build errors on other ports, so: heads up.

NOTE TO DEVELOPERS: please do not grow new uses of #ifdef COMPAT_FOO outside
of code that is to be included in one of the compat modules.

NOTE TO PORTMASTERS: to make the compat stuff loadable as modules, COMPAT_
ifdefs have to be purged from arch/${port}. Generally speaking, if the
compat ifdef is in a file that is to be loaded as part of a compat module,
say compat_16_machdep.c then it's ok. If it's elsewhere, like vm_machdep.c,
then it needs to be neutralized - either removed or moved or replaced with a
hook. I have done this for x86 and touched on the other ports but have not
completely verified any ports other than the x86 ones. If you plan to
support only !modular kernels there is no need to do anything.

Thanks,
Andrew