ansi_alias is now ansi-alias, at least since 2015

m4/ax_cc_maxopt.m4

@@ -105,7 +105,7 @@ if test "$ac_test_CFLAGS" != "set"; then
                 echo "******************************************************"])
          ;;
 
-    intel) CFLAGS="-O3 -ansi_alias"
+    intel) CFLAGS="-O3 -ansi-alias"
 	if test "x$acx_maxopt_portable" = xno; then
 	  icc_archflag=unknown
 	  icc_flags=""