Remove obsolete IRIX 6.5 support

[Jonathan Wakely]

On 12 March 2012 17:03, Rainer Orth wrote:
> Continuing with the patches to remove obsolete ports, here's the IRIX
> 6.5 removal patch.
...
> * libstdc++-v3/doc/xml/manual/internals.xml still uses IRIX as an
>  example.  I've kept that part since I guess it's up the libstdc++
>  maintainers to decide what to do about this.

Thanks for pointing it out.

The libstdc++ parts of the patch are OK.