Fix IRIX pathconf() syscall

[cadmic]

Currently pathconf() always errors in qemu, and when running IDO with -g3 this causes it to allocate to a heap buffer with a size too small. When the compiler encounters a long path name it overflows this buffer, which can corrupt the heap and eventually lead to a segfault. Currently this prevents OOT retail versions from building with qemu-irix.

I some trouble getting this to build on modern Ubuntu. I updated a submodule path in this PR, and also had to install python2 manually. Full steps (from https://ubuntuforums.org/showthread.php?t=2486174&p=14140057#post14140057):

wget https://www.python.org/ftp/python/2.7.9/Python-2.7.9.tgz
sudo tar xzf Python-2.7.9.tgz
cd Python-2.7.9
sudo ./configure --enable-optimizations
sudo make altinstall

Then to build qemu-irix:

./configure --target-list=irix-linux-user --disable-werror --python=/usr/local/bin/python2.7
make
sudo make install