broken strndup on AIX 5.1

[Doug VanLeuven]

Also, AIX 5.1 still has a broken strnlen as noted at gnu.org under 
autoconf 5.5.1 Portability of C Functons.
I need some help with configure.in.

Doug VanLeuven wrote:

> Hi,
> AIX 5.1.0.50
> samba 3_0 svn 1824
> strndup in libc.a
>
> I could pass all the smbtorture tests except MANGLE.
> This patch on an AIX illustrates the problem if smb.conf uses hash2 
> method and allows MANGLE to succeed.
> Neither are the build_farm AIX systems passing this test.
>
> Would someone point me towards the proper way to solve this in 
> configure?  Try and test for broken strndup behavior or just use the 
> builtin for AIX 5L?