m4: Utilize AS_VAR_APPEND

* m4/libtool.m4: Instead of a conditional for using -no_fixup_chains,
  AC_VAR_APPEND will handle appending the option to the variable, which
  allows the '+=' extension to be used by shells that provide this
  capability for more efficient scaling. Also, bump minimum required
  version of autoconf from 2.62 to 2.64.

diff --git a/m4/libtool.m4 b/m4/libtool.m4
index e9eef32fae40926d3bbc3412946adf382012fe07..29525980e6169c8e08c0b36d6cf0a30fe2541b77 100644 (file)
--- a/m4/libtool.m4
+++ b/m4/libtool.m4
@@ -60,7 +60,7 @@ esac
 # LT_INIT([OPTIONS])
 # ------------------
 AC_DEFUN([LT_INIT],
-[AC_PREREQ([2.62])dnl We use AC_PATH_PROGS_FEATURE_CHECK
+[AC_PREREQ([2.64])dnl We use AC_PATH_PROGS_FEATURE_CHECK
 AC_REQUIRE([AC_CONFIG_AUX_DIR_DEFAULT])dnl
 AC_BEFORE([$0], [LT_LANG])dnl
 AC_BEFORE([$0], [LT_OUTPUT])dnl
@@ -1089,10 +1089,9 @@ _LT_EOF
         10.[[012]],*|,*powerpc*-darwin[[5-8]]*)
           _lt_dar_allow_undefined='$wl-flat_namespace $wl-undefined ${wl}suppress' ;;
         *)
+          _lt_dar_allow_undefined='$wl-undefined ${wl}dynamic_lookup'
           if test yes = "$lt_cv_support_no_fixup_chains"; then
-            _lt_dar_allow_undefined='$wl-undefined ${wl}dynamic_lookup $wl-no_fixup_chains'
-          else
-            _lt_dar_allow_undefined='$wl-undefined ${wl}dynamic_lookup'
+            AS_VAR_APPEND([_lt_dar_allow_undefined], [' $wl-no_fixup_chains'])
           fi
         ;;
       esac