Ensure that the makewhatis symlink is added in the bootstrap-tools stage

We currently set MK_MAN=no in $BSARGS so MK_MAN_UTILS will also be false
which means that the makewhatis symlink will not be created.
This change fixes the build when using both -DBUILD_WITH_STRICT_TMPPATH and
-DBOOTSTRAP_ALL_TOOLS.

Tested by:	andrew
Differential Revision: https://reviews.freebsd.org/D16761

Makefile.inc1

@@ -723,7 +723,7 @@ BSARGS= 	DESTDIR= \
 		BOOTSTRAPPING=${BOOTSTRAPPING_OSRELDATE} \
 		BWPHASE=${.TARGET:C,^_,,} \
 		SSP_CFLAGS= \
-		MK_HTML=no NO_LINT=yes MK_MAN=no \
+		MK_HTML=no NO_LINT=yes MK_MAN=no MK_MAN_UTILS=yes \
 		-DNO_PIC MK_PROFILE=no -DNO_SHARED \
 		-DNO_CPU_CFLAGS MK_WARNS=no MK_CTF=no \
 		MK_CLANG_EXTRAS=no MK_CLANG_FORMAT=no MK_CLANG_FULL=no \

usr.bin/mandoc/Makefile

@@ -14,6 +14,8 @@ MLINKS+=	apropos.1 whatis.1
 LINKS=	${BINDIR}/mandoc ${BINDIR}/whatis \
 	${BINDIR}/mandoc ${BINDIR}/makewhatis \
 	${BINDIR}/mandoc ${BINDIR}/apropos
+.elif defined(BOOTSTRAPPING)
+.error "MK_MAN_UTILS should be set to yes when bootstrapping"
 .endif
 
 LIBMAN_SRCS=	man.c \