[PD] Pd for IRIX is alive again

[Miller Puckette]

Hi all,

after many months of not quite having the IRIX version of Pd together,
I've managed to compile 0.34 test 6 for IRIX.  It compiled and seems to
work in both o32 ("pd") and n32 ("pd-n32") versions.

Thanks to Fernando at CCRMA for making an up-to-date IRIX machine available!

cheers
Miller