Soon we are going to split virtmem code into its own DSO to which
bigfile extension will link. As plain setuptools does not support such
dynamic linking, we are going to use setuptools_dso instead. But more:
some of our upcoming extensions and DSOs will need to use Cython and C++
parts of Pygolang. Prepare that and use Extensions and DSO from
golang.pyx.build to support that right from the start.