Replace again GNU diff with BSD diff

After a firts failed attempt, BSD diff is now good enough to replace
GNU diff.

Relnotes:	yes

Makefile.inc1

@@ -1972,7 +1972,7 @@ native-xtools: .PHONY
     ${_clang} \
     sbin/md5 \
     sbin/sysctl \
-    gnu/usr.bin/diff \
+    usr.bin/diff \
     usr.bin/awk \
     usr.bin/basename \
     usr.bin/bmake \

ObsoleteFiles.inc

@@ -38,6 +38,8 @@
 #   xargs -n1 | sort | uniq -d;
 # done
 
+# 20170420: remove GNU diff
+OLD_FILES+=usr/share/man/man7/diff.7.gz
 # 20170322: rename <x> to <x>_test to match the FreeBSD test suite name scheme
 OLD_FILES+=usr/tests/usr.bin/col/col
 OLD_FILES+=usr/tests/usr.bin/diff/diff

UPDATING

@@ -51,6 +51,11 @@ NOTE TO PEOPLE WHO THINK THAT FreeBSD 12.x IS SLOW:
 
 ****************************** SPECIAL WARNING: ******************************
 
+20170420:
+	GNU diff has been replaced by a BSD licensed diff. Some features of GNU
+	diff has not been implemented, if those are needed a newer version of
+	GNU diff is available via the diffutils package under the gdiff name.
+
 20170413:
 	As of r316810 for ipfilter, keep frags is no longer assumed when
 	keep state is specified in a rule. r316810 aligns ipfilter with

gnu/usr.bin/Makefile

@@ -17,7 +17,7 @@ SUBDIR_DEPEND_gdb=	binutils
 .endif
 
 SUBDIR.${MK_GCC}+=	cc
-SUBDIR.${MK_GNU_DIFF}+=	diff diff3
+SUBDIR.${MK_GNU_DIFF}+=	diff3
 SUBDIR.${MK_GNU_GREP}+=	grep
 SUBDIR.${MK_GPL_DTC}+=	dtc
 SUBDIR.${MK_TESTS}+=	tests

gnu/usr.bin/diff/Makefile

@@ -1,36 +0,0 @@
-# $FreeBSD$
-
-.include <src.opts.mk>
-
-DIFFSRC=${.CURDIR}/../../../contrib/diff/src
-.PATH: ${DIFFSRC} \
-       ${.CURDIR}/../../../contrib/diff/lib \
-       ${.CURDIR}/../../../contrib/diff/man \
-       ${.CURDIR}/../../../contrib/diff/doc
-
-PROG=	diff
-SRCS=   analyze.c context.c diff.c dir.c ed.c ifdef.c io.c \
-	normal.c side.c util.c \
-	xmalloc.c strtoumax.c cmpbuf.c exitfail.c error.c quotesys.c \
-	strftime.c c-stack.c basename.c exclude.c hard-locale.c \
-	file-type.c posixver.c prepargs.c version-etc.c
-
-# Important for ctype macros!
-CFLAGS+=-funsigned-char
-
-CFLAGS+=-DHAVE_CONFIG_H
-CFLAGS+=-DPR_PROGRAM=\"/usr/bin/pr\"
-CFLAGS+=-I${.CURDIR}/../../../contrib/diff
-CFLAGS+=-I${.CURDIR}/../../../contrib/diff/src
-CFLAGS+=-I${.CURDIR}/../../../contrib/diff/lib
-CFLAGS+=-I${DESTDIR}/usr/include/gnu
-
-MAN=	diff.1 diff.7
-
-LIBADD+=	gnuregex
-
-.if ${MK_TESTS} != "no"
-SUBDIR+=	tests
-.endif
-
-.include <bsd.prog.mk>

gnu/usr.bin/diff/Makefile.depend

@@ -1,19 +0,0 @@
-# $FreeBSD$
-# Autogenerated - do NOT edit!
-
-DIRDEPS = \
-	gnu/lib/csu \
-	gnu/lib/libgcc \
-	gnu/lib/libregex \
-	include \
-	include/xlocale \
-	lib/${CSU_DIR} \
-	lib/libc \
-	lib/libcompiler_rt \
-
-
-.include <dirdeps.mk>
-
-.if ${DEP_RELDIR} == ${_DEP_RELDIR}
-# local dependencies - needed for -jN in clean tree
-.endif

gnu/usr.bin/diff/tests/Makefile

@@ -1,15 +0,0 @@
-# $FreeBSD$
-
-PACKAGE=	tests
-
-TESTSRC=	${SRCTOP}/contrib/netbsd-tests/usr.bin/diff
-
-NETBSD_ATF_TESTS_SH=	diff_test
-ATF_TESTS_SH_SED_diff_test=	-e 's/t_diff/`basename $$0`/g'
-
-${PACKAGE}FILES+=	d_mallocv1.in
-${PACKAGE}FILES+=	d_mallocv2.in
-
-.include <netbsd-tests.test.mk>
-
-.include <bsd.test.mk>

gnu/usr.bin/diff/tests/Makefile.depend

@@ -1,11 +0,0 @@
-# $FreeBSD$
-# Autogenerated - do NOT edit!
-
-DIRDEPS = \
-
-
-.include <dirdeps.mk>
-
-.if ${DEP_RELDIR} == ${_DEP_RELDIR}
-# local dependencies - needed for -jN in clean tree
-.endif

usr.bin/Makefile

@@ -34,6 +34,7 @@ SUBDIR=	alias \
 	csplit \
 	ctlstat \
 	cut \
+	diff \
 	dirname \
 	du \
 	elf2aout \