(_AC_PROG_CC_STDC): Prefer -qlanglvl=extc89

to -qlanglvl=ansi.  We don't want to disable extensions.

diff --git a/lib/autoconf/c.m4 b/lib/autoconf/c.m4
index 06ea36941ab1106862b82daf46550be757e176a7..e3f5666adb301b509fad69772a4b8fe063c94f0f 100644 (file)
--- a/lib/autoconf/c.m4
+++ b/lib/autoconf/c.m4
@@ -864,12 +864,14 @@ char **argv;]],
 [[return f (e, argv, 0) != argv[0]  ||  f (e, argv, 1) != argv[1];]])])
 # Don't try gcc -ansi; that turns off useful extensions and
 # breaks some systems' header files.
-# AIX                  -qlanglvl=ansi
+# AIX circa 2003       -qlanglvl=extc89
+# old AIX              -qlanglvl=ansi
 # Ultrix, OSF/1, Tru64 -std
 # HP-UX 10.20 and later        -Ae
 # HP-UX older versions -Aa -D_HPUX_SOURCE
 # SVR4                 -Xc -D__EXTENSIONS__
-for ac_arg in "" -qlanglvl=ansi -std -Ae "-Aa -D_HPUX_SOURCE" "-Xc -D__EXTENSIONS__"
+for ac_arg in "" -qlanglvl=extc89 -qlanglvl=ansi -std \
+       -Ae "-Aa -D_HPUX_SOURCE" "-Xc -D__EXTENSIONS__"
 do
   CC="$ac_save_CC $ac_arg"
   _AC_COMPILE_IFELSE([],