user32: Implement GetWindowModuleFileName with tests

[Dmitry Timoshkov]

"Maarten Lankhorst" <m.b.lankhorst at gmail.com> wrote:

> I've tried to do the GetWindowLongPtr GWLP_HINSTANCE thing but it
> seems to always return 0 in wine, which according to msdn means error,
> but it could just be not set in wine. Perhaps GWLP_HINSTANCE needs to
> be set when the window is being created?

It works just fine in Wine, have a look at dlls/user32/tests/class.c,
test_instances().

-- 
Dmitry.