build: Use `AM_PROG_AR'.

* configure.ac: Use `AM_PROG_AR', as suggested by Automake
  1.12.1 ("warning: 'libguilereadline-v-@LIBGUILEREADLINE_MAJOR@.la':
  linking libtool libraries using a non-POSIX archiver requires
  'AM_PROG_AR' in 'configure.ac'").

diff --git a/configure.ac b/configure.ac
index af7c3a8..32a6760 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -64,6 +64,7 @@ AC_PROG_CPP
 AC_PROG_SED
 AC_PROG_AWK
 AC_PROG_LN_S
+AM_PROG_AR
 
 dnl Gnulib.
 gl_INIT