Improve the process for GNU tools

Split the process to fetch GNU tools (until now embedded
within tools/Makefile.gnuhost) into a new Makefile.fetchgnu,
MINIX-specific hence relocated, which is to be also used
to fetch sources even when not building the tools.
Use it for binutils too.
Improve documentation.

Also do not run configure on each run when MKUPDATE=yes
The .WAIT serialization instruction between fetching and other
configure sources was raising a new run of configure at each
compilation. Avoid it by using two rules.

Change-Id: Ie24950ccbb5c5067f3c1ea57b7bd8294e4c9445e

gnu/Makefile

@@ -1,9 +1,5 @@
 #	$NetBSD: Makefile,v 1.17 2010/12/03 21:38:47 plunky Exp $
 
-.if defined(__MINIX)
-#LSC: Trigger fetch.sh script
-SUBDIR+= dist .WAIT
-.endif # defined(__MINIX)
 SUBDIR+= usr.bin
 
 # Speedup stubs for some subtrees that don't need to run these rules

gnu/dist/Makefile

@@ -1,18 +0,0 @@
-# LSC FIXME: Hackish way to trigger the fetch phase from here
-# 	     in the same way as from tools.
-
-.include <bsd.own.mk>
-
-MODULE=	texinfo
-
-.include "${.CURDIR}/../../tools/Makefile.gnuhost"
-
-# Force the mapping to standard targets even when not building tools
-# We considere work to be done as soon as the fetch step is done,
-# as everything else has to be triggered from /tools or ../usr.bin
-
-.if ${USETOOLS} != "yes"
-realall realinstall: ${GNUHOSTDIST:H}/.gitignore
-
-.endif
-

gnu/usr.bin/texinfo/makedoc/Makefile

@@ -5,6 +5,13 @@ MAKEDOC=
 
 .include "../Makefile.inc"
 
+.if defined(__MINIX)
+#LSC: First program within texinfo: trigger fetch.sh script
+MODULE=		texinfo
+GNUHOSTDIST=	${DIST}/${MODULE}
+.include "${.CURDIR}/../../../../minix/Makefile.fetchgnu"
+.endif # defined(__MINIX)
+
 HOSTPROG=	makedoc
 SRCS=		makedoc.c xexit.c xmalloc.c xstrdup.c
 
@@ -13,3 +20,8 @@ HOST_CPPFLAGS+= -I${IDIST}/info -I${IDIST}/lib -I${.CURDIR}/../common
 HOST_CPPFLAGS+= -DHOSTTOOL
 
 .include <bsd.hostprog.mk>
+
+.if defined(__MINIX) && ${USETOOLS} != "yes"
+# MINIX: make sure sources are fetched, even when tools not built earlier
+${SRCS} realdepend realall realinstall: ${fetch_done}
+.endif # defined(__MINIX)