app-misc/bb: unbreak m4 handling

Fix 'm4-stuff.patch' to restore m4/ directory.
Was broken by upgrade to EAPI=7. Instead of failing
patch dumped files into root directory instead of m4/.

Reported-by: Gabriele Pelissetto
Closes: https://bugs.gentoo.org/699826
Package-Manager: Portage-2.3.79, Repoman-2.3.18
Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>

app-misc/bb/bb-1.3.0_rc1-r5.ebuild

@@ -63,7 +63,8 @@ src_prepare() {
 		-i Makefile.am || die
 
 	mv -v configure.{in,ac} || die
-	eautoreconf
+	# m4/ dir is added with 'm4-stuff.patch' patch
+	AT_M4DIR="m4" eautoreconf
 }
 
 pkg_postinst() {

app-misc/bb/files/bb-1.3.0_rc1-m4-stuff.patch

@@ -7,7 +7,7 @@ Date:   Tue Feb 7 10:59:09 2012 +0300
     bb-1.3.0_rc1: bundle m4 source
 
 --- /dev/null
-+++ m4/aalib.m4
++++ a/m4/aalib.m4
 @@ -0,0 +1,169 @@
 +# Configure paths for AALIB
 +# Jan Hubicka 4/22/2001
@@ -179,7 +179,7 @@ Date:   Tue Feb 7 10:59:09 2012 +0300
 +  rm -f conf.aalibtest
 +])
 --- /dev/null
-+++ m4/libmikmod.m4
++++ a/m4/libmikmod.m4
 @@ -0,0 +1,207 @@
 +# Configure paths for libmikmod
 +#