installincludes, bsd.incs.mk and param.h

 Hello,

since bsd.port.mk insinsts on param.h, I have inconveniences on my
production systems which were installed with "WITHOUT_TOOLCHAIN=true" in
src.conf (resulting in MK_TOOLCHAIN=no).

My first attempt was the following patch:
--- share/mk/bsd.incs.mk.orig   2014-10-14 16:35:53.000000000 +0200
+++ share/mk/bsd.incs.mk        2014-10-14 16:34:57.000000000 +0200
_at__at_ -81,4 +81,9 _at__at_
 realinstall: installincludes
 .ORDER: beforeinstall installincludes
 
+.else
+installincludes:
+        ${INSTALL} -C -o ${BINOWN} -g ${BINGRP} -m ${NOBINMODE} \
+            ${SYSDIR}/sys/param.h ${DESTDIR}${INCLUDEDIR}/sys/sys
+
 .endif # !defined(NO_INCS) && ${MK_TOOLCHAIN} != "no"

"$SYSDIR" makes the example above not working!
Unfortunately I couldn't figure out when/how param.h gets installed.
Also, I couldn't find out what stage uses include/Makefile, only that
it's not used when  MK_TOOLCHAIN=no.

Any help highly appreciated!

Thanks,

-Harry