auto detect lang:std:

configure

@@ -1935,7 +1935,7 @@ case $system in
         fi
         rm -f conftest*
 	;;
-    IRIX-6* | IRIX64-6* | IRIX-64-6*)
+    IRIX-5* | IRIX-6* | IRIX64-6* | IRIX-64-6*)
         echo $ac_n "checking whether ${CC} accepts -LANG:std""... $ac_c" 1>&6
         echo 'void f(){}' > conftest.c
         if test -z "`${CC} -LANG:std -c conftest.c 2>&1`"; then

configure.in

@@ -31,7 +31,7 @@ case $system in
         fi
         rm -f conftest*
 	;;  
-    IRIX-6* | IRIX64-6* | IRIX-64-6*)
+    IRIX-5* | IRIX-6* | IRIX64-6* | IRIX-64-6*)
         echo $ac_n "checking whether ${CC} accepts -LANG:std""... $ac_c" 1>&6
         echo 'void f(){}' > conftest.c
         if test -z "`${CC} -LANG:std -c conftest.c 2>&1`"; then