[master] Add m4/README to distribution tarball to avoid ac_local() fails

Merges in rt47075.

Makefile.am

@@ -29,7 +29,8 @@ EXTRA_DIST = RELNOTES LICENSE configure.ac+lt config+lt \
 	     doc/devel/debug.dox doc/devel/isc-logo.jpg doc/devel/libtool.dox \
 	     doc/devel/mainpage.dox doc/devel/omapi.dox doc/devel/qa.dox \
 	     client/tests/Atffile common/tests/Atffile server/tests/Atffile \
-	     client/tests/Kyuafile common/tests/Kyuafile server/tests/Kyuafile
+	     client/tests/Kyuafile common/tests/Kyuafile server/tests/Kyuafile \
+         m4/README
 
 if HAVE_BINDDIR
 EXTRA_DIST += bind/Makefile.in bind/bind.tar.gz bind/version.tmp

Makefile.in

@@ -385,7 +385,7 @@ EXTRA_DIST = RELNOTES LICENSE configure.ac+lt config+lt \
 	doc/devel/mainpage.dox doc/devel/omapi.dox doc/devel/qa.dox \
 	client/tests/Atffile common/tests/Atffile server/tests/Atffile \
 	client/tests/Kyuafile common/tests/Kyuafile \
-	server/tests/Kyuafile $(am__append_1)
+	server/tests/Kyuafile m4/README $(am__append_1)
 
 # Use an autoconf substitution vs an automake conditional here
 # to fool automake when the bind directory does not exist.

RELNOTES

@@ -122,6 +122,12 @@ by Eric Young (eay@cryptsoft.com).
   was causing BIND9 build to not generate dns/enumclass.h and dns/enumtype.h.
   [ISC-Bugs #46971]
 
+- Added <dhcp>/m4/README to the distribution tarball.  Some versions of
+  ac_local() treat the absence of the m4 subdirectory as error rather than
+  warning.  This was causing the call to autoreconf, necessary for building
+  with libtool, to fail.
+  [ISC-Bugs #47075]
+
 		Changes since 4.4.0a1 (New Features)
 
 - Added experimental support for relay port (draft-ietf-dhc-relay-port-10.txt)

m4/README

@@ -0,0 +1,2 @@
+Currently we have no m4 macros. This directory is here to accommodate
+some versions of ac_local() which treat its absence as an error.