External dependencies for dmd tests

[Benjamin Thaut]

I would like to extend the DMD testsuite with a test for cv8 debug 
information. For that however I need a extarnal executable. Dia2Dump 
wich is part of the examples of visual studio. How is such a situation 
usually handeled? Is the binary stored prebuild somewhere? This test 
would only run on windows, so it would be feasable to brebuild the 
binary. Or is it required to be able to rebuild the external dependencies?

Kind Regards
Benjamin Thaut