Revert r257730:

Make head/ buildable again, instead of spewing garbage like:
 /src/gnu/lib/csu/../../../contrib/gcc/config/rs6000/crtsavres.asm:280:
  Error: no such instruction: `lwz 28,-16(11)'

Makefile.inc1

@@ -439,16 +439,6 @@ IMAKE_MTREE=	MTREE_CMD="nmtree ${MTREEFLAGS}"
 KMAKEENV=	${WMAKEENV}
 KMAKE=		${KMAKEENV} ${MAKE} ${.MAKEFLAGS} ${KERNEL_FLAGS} KERNEL=${INSTKERNNAME}
 
-# kernel build-tools stage
-KTMAKE=		MAKEOBJDIRPREFIX=${WORLDTMP} \
-		${WMAKEENV} ${MAKE} -f Makefile.inc1 \
-		TARGET=${TARGET} TARGET_ARCH=${TARGET_ARCH} \
-		DESTDIR= \
-		BOOTSTRAPPING=${OSRELDATE} \
-		SSP_CFLAGS= \
-		-DNO_LINT \
-		-DNO_CPU_CFLAGS -DNO_WARNS -DNO_CTF -DEARLY_BUILD
-
 #
 # buildworld
 #
@@ -1029,7 +1019,7 @@ buildkernel:
 	@echo "--------------------------------------------------------------"
 	@echo ">>> stage 2.3: build tools"
 	@echo "--------------------------------------------------------------"
-	${_+_}cd ${.CURDIR}; ${KTMAKE} kernel-tools
+	@# Currently no special kernel tools to build.
 .if !defined(NO_KERNELDEPEND)
 	@echo
 	@echo "--------------------------------------------------------------"
@@ -1356,23 +1346,6 @@ build-tools: .MAKE
 		${MAKE} DIRPRFX=${_tool}/ all
 .endfor
 
-#
-# kernel-tools: Build kernel-building tools
-#
-kernel-tools: .MAKE
-	mkdir -p ${WORLDTMP}/usr
-	mtree -deU -f ${.CURDIR}/etc/mtree/BSD.usr.dist \
-	    -p ${WORLDTMP}/usr >/dev/null
-.for _tool in \
-    sys/dev/aic7xxx/aicasm
-	${_+_}@${ECHODIR} "===> ${_tool} (obj,depend,all,install)"; \
-		cd ${.CURDIR}/${_tool} && \
-		${MAKE} DIRPRFX=${_tool}/ obj && \
-		${MAKE} DIRPRFX=${_tool}/ depend && \
-		${MAKE} DIRPRFX=${_tool}/ all && \
-		${MAKE} DIRPRFX=${_tool}/ DESTDIR=${WORLDTMP} install
-.endfor
-
 #
 # cross-tools: Build cross-building tools
 #
@@ -1420,6 +1393,7 @@ cross-tools: .MAKE
     ${_btxld} \
     ${_crunchide} \
     ${_kgzip} \
+    sys/dev/aic7xxx/aicasm
 	${_+_}@${ECHODIR} "===> ${_tool} (obj,depend,all,install)"; \
 		cd ${.CURDIR}/${_tool} && \
 		${MAKE} DIRPRFX=${_tool}/ obj && \