Deal with bootstrapping from an old -current (almost exactly a year old)

which fails the make tests (doesn't understand ${notdef:U}) and therefore
fails on __FBSDID in usr.bin/make/*.  -DBOOTSTRAPPING is no help here since
this is before we are using the new share/mk/* files, and it would conflict
with the builtin -DBOOTSTRAPPING support later.. so use a different flag.

Makefile

@@ -204,7 +204,8 @@ make:
 	@echo " Upgrading the installed make"
 	@echo "--------------------------------------------------------------"
 	@cd ${.CURDIR}/usr.bin/make; \
-		make obj && make depend && make all && make install
+		make obj && make -D_UPGRADING depend && \
+		make -D_UPGRADING all && make install
 
 #
 # Define the upgrade targets. These are listed here in alphabetical

usr.bin/make/Makefile

@@ -16,6 +16,9 @@ SRCS+=	lstAppend.c lstAtEnd.c lstAtFront.c lstClose.c lstConcat.c \
 NOSHARED?=	YES
 
 CFLAGS+=-DMAKE_VERSION=\"5200208240\"
+.if defined(_UPGRADING)
+CFLAGS+=-D__FBSDID=__RCSID
+.endif
 
 main.o: ${MAKEFILE}