MinGW cross compilation fails for d3dx9_36/tests

[Paul Vriens]

Hi,

We didn't have a new winetest executable for the last few days. MinGW doesn't 
know anything about a d3dx9 dll (yet) that's imported in the d3dx9_36 tests.

Especially while in the process of getting ready for 1.0 we should have winetest 
run as much as possible.

My main focus will be adding tests btw until 1.0 is out. These will be both 
tests to proof the correctness of the current implementation as well as tests to 
show missing stuff. There are loads of functions for which we have no tests yet 
and with the 1.0 in sight I think it becomes very important to have tests for 
virtually every function we (have) implement(ed).