[libxml2] Move local Autoconf macros into m4 directory

[Nick Wellnhofer <nwellnhof src gnome org>]

commit 0d467de29994f222f8faeb991539da31e5ab68ab
Author: Nick Wellnhofer <wellnhofer aevum de>
Date:   Sun Apr 3 19:11:13 2022 +0200

    Move local Autoconf macros into m4 directory

 .gitignore                            | 3 ++-
 acinclude.m4 => m4/ac_try_compile2.m4 | 0
 2 files changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/.gitignore b/.gitignore
index 19c0403a..20bdf9df 100644
--- a/.gitignore
+++ b/.gitignore
@@ -70,7 +70,8 @@ ltmain.sh
 log
 missing
 missing.lst
-m4
+m4/libtool.m4
+m4/lt*.m4
 py-compile
 python/.deps
 python/.libs
diff --git a/acinclude.m4 b/m4/ac_try_compile2.m4
similarity index 100%
rename from acinclude.m4
rename to m4/ac_try_compile2.m4