Support the 'config.site' file in /usr/share

1. Generated configure scripts will now automatically set the correct
   library directory ($libdir) on both 32/64 bit systems when
   './configure --prefix=/usr' is run.

2. The same way as ^^, config.site causes the installation under /usr prefix
   to respect File System Hierarchy (FHS) defaults

autoconf.spec

@@ -4,7 +4,8 @@ Version:    2.69
 Release:    6%{?dist}
 License:    GPLv2+ and GFDL
 Group:      Development/Tools
-Source:     http://ftpmirror.gnu.org/autoconf/autoconf-%{version}.tar.xz
+Source0:    http://ftpmirror.gnu.org/autoconf/autoconf-%{version}.tar.xz
+Source1:    config.site
 URL:        http://www.gnu.org/software/autoconf/
 BuildArch: noarch
 BuildRoot:  %{_tmppath}/%{name}-%{version}-%{release}-root-%(%{__id_u} -n)
@@ -67,6 +68,8 @@ make check # TESTSUITEFLAGS='1-198 200-' # will disable nr. 199.
 
 %install
 make install DESTDIR=%{buildroot}
+mkdir -p %{buildroot}/share
+install -m 0644 %{SOURCE1} %{buildroot}%{_datadir}
 
 %post
 /sbin/install-info %{_infodir}/autoconf.info %{_infodir}/dir || :
@@ -84,6 +87,7 @@ fi
 # don't include info's TOP directory
 %exclude %{_infodir}/dir
 %{_datadir}/autoconf/
+%{_datadir}/config.site
 %exclude %{_datadir}/autoconf/INSTALL
 %dir %{_datadir}/emacs/
 %{_datadir}/emacs/site-lisp/

config.site

@@ -0,0 +1,22 @@
+# This is the config.site file to satisfy FHS defaults when installing below
+# /usr.
+#
+# You may override this file by your config.site using the CONFIG_SITE env
+# variable.
+#
+# Note: This file includes also RHEL/Fedora fix for installing libraries into
+# "/lib/lib64" on 64bit systems.
+
+if test "$prefix" = /usr; then
+    test "$sysconfdir" = '${prefix}/etc' && sysconfdir=/etc
+    test "$sharedstatedir" = '${prefix}/com' && sharedstatedir=/var
+    test "$localstatedir" = '${prefix}/var' && localstatedir=/var
+
+    ARCH=`uname -m`
+    for i in x86_64 ppc64 s390x aarch64; do
+        if test $ARCH = $i; then
+            test "$libdir" = '${exec_prefix}/lib' && libdir='${exec_prefix}/lib64'
+            break
+        fi
+    done
+fi