Adding ../../sys to the include path - is it necessary?

Hi,

I've noticed a lot of Makefiles (in src/sbin and src/usr.sbin
especially) have

	CFLAGS+= -I${.CURDIR}/../../sys

presumably so they pick up the latest kernel headers during a 'make
buildworld'.

But this also makes them uncompilable on my system when just issuing a
simple 'make' in the program's directory - it complains about a conflict
between the definitions of pid_t in

 	../../sys/sys/types.h:85 and
	/usr/include/stdio.h:54.

This makes piecemeal testing awkward...

But also, doesn't the new buildworld system pick up any new sys headers
by itself, making it unnecessary to specify this extra include directory
in each program's Makefile?

I'll run a full buildworld/kernel cycle tonight to try to find out.

I'll be happy to find and delete them if they turn out to be no longer
needed.

-Chris