lib32: Fix lib/libpmc/pmu-events files ending up in source directory.

This could happen with either WITHOUT_AUTO_OBJ=yes or MAKELEVEL>0 for
the initial 'make buildworld' command.

This now ensures that build-tools targets have 'make obj' ran if needed.

This is especially problematic for pmu-events since it is not directly
connected in the build.  Normally the 'make includes' call right before
this implicitly creates the objdir with a 'make obj' already but
misses pmu-events because it is disconnected from lib/libpmc.  Fixing that
would make this new 'make obj' pointless but it is being added to avoid
this problem in the future should another tool be connected like this.

Reported by:	rgrimes, kib, kevans
Sponsored by:	Dell EMC

Makefile.libcompat

@@ -201,6 +201,7 @@ build${libcompat}: .PHONY
 .endfor
 .endfor
 .for _dir in lib/ncurses/ncurses lib/ncurses/ncursesw ${_libmagic} ${_jevents}
+.for _t in ${_obj} build-tools
 	${_+_}cd ${.CURDIR}/${_dir}; \
 	    WORLDTMP=${WORLDTMP} \
 	    MAKEFLAGS="-m ${.CURDIR}/tools/build/mk ${.MAKEFLAGS}" \
@@ -209,7 +210,8 @@ build${libcompat}: .PHONY
 	    OBJROOT='$${OBJTOP}/' \
 	    MAKEOBJDIRPREFIX= \
 	    DIRPRFX=${_dir}/ -DNO_LINT -DNO_CPU_CFLAGS MK_WARNS=no MK_CTF=no \
-	    build-tools
+	    ${_t}
+.endfor
 .endfor
 	${_+_}cd ${.CURDIR}; \
 	    ${LIBCOMPATWMAKE} -f Makefile.inc1 -DNO_FSCHG libraries