Hi,
Sorry, no GCC or python available on IRIX. We do ship the open source Python bindings with the SDK, so you can create your own python module if you'd like. This allows you to use a different version of Python too. You'll need Boost as well. The SDK should tell you where to get it.
Cheers,
Dan
P.S. The WT API works remotely, so there is usually very little reason to develop a WT tool on IRIX.