[svn-r19590] Bug fix: 1961-- AIX 6.1 --enable-share did not work.

(Forgot to commit this file when bin/config.guess was committed.)

Description:
In an AIX 6.1 system, configure --enable-shared could not build a shared
HDF5 library. The problem was because the version of config.guess was too
old to recongnize AIX 6.X and also configure.in had a local fix which did
not recognize AIX 6.X.

Solution:
1. Mike McGreevy updated bin/config.guess to handle AIX 6.X.
2 Albert fixed configure.in to recognize AIX 6.X.

Note that though HDF5 can build shared lib for AIX 6.X systems
but it still could not install the proper library as in AIX 5.X
systems. Also, bin/config.sub should be updated too.

Tested: BP which is the AIX 6.1 system that exposed this problem.

config/ibm-aix6.x

@@ -0,0 +1,21 @@
+#							-*- shell-script -*-
+#
+# Copyright by The HDF Group.
+# All rights reserved.
+#
+# This file is part of HDF5.  The full HDF5 copyright notice, including
+# terms governing use, modification, and redistribution, is contained in
+# the files COPYING and Copyright.html.  COPYING can be found at the root
+# of the source code distribution tree; Copyright.html can be found at the
+# root level of an installed copy of the electronic HDF5 document set and
+# is linked from the top-level documents page.  It can also be found at
+# http://hdfgroup.org/HDF5/doc/Copyright.html.  If you do not have
+# access to either file, you may request a copy from help@hdfgroup.org.
+
+# Configuration file for building on the IBM AIX 6.X platforms.
+# This file is part of the HDF5 build script.  It is processed shortly
+# after configure starts and defines, among other things, flags for
+# the various compile modesrcdir/config/ibm-aix
+
+# Use the generic ibm-aix.
+. $srcdir/config/ibm-aix