Update tested AIX memset platforms.

Author: bmomjian

src/template/aix

@@ -9,6 +9,7 @@ if test "$GCC" != yes ; then
   esac
 fi
 
-# native memset() is faster, 2006-02-03
-# XLC 6.0, (IBM's cc), tested on AIX 5.2 and 5.1
+# Native memset() is faster, tested on:
+# 	AIX 5.1 and 5.2, XLC 6.0 (IBM's cc)
+# 	AIX 5.3 ML3, gcc 4.0.1
 MEMSET_LOOP_LIMIT=0