Files missing in /usr/include?

[Matt Smith <mattjsm%gmail.com@localhost>]

Hello,

I'm working on porting the OpenAFS client over to NetBSD 5.0.2. In
trying to compile the LKM for it, the files cpu.h and intr.h in
/usr/include/x86/ are included. These headers include additional
headers. The problem, however, is that a couple of the headers they
try to include are not in /usr/include/x86. For example:

/usr/include/x86/cpu.h includes /x86/via_padlock.h
/usr/include/x86/intr.h includes /machine/pic.h

Instead, these included headers are located in the src tree
(/usr/src/sys/arch/x86/include). They can be linked in to satisfy the
dependency, but intr.h errors out due to missing some expected
characters.

Does anyone know why these files would be missing from /usr/include?
Additionally, why would non-compilable files be placed for use in
/usr/include?

Thanks!
Matt Smith