Wine 0.9.6 glext.h / DirectX Compiler Error

[H. Verbeet]

Actually, looking at the code for the original patch a bit closer, the
original patch is incorrect. GL_SUPPORT should get passed a memeber of
the enum GL_SupportedExt. Wether an extension is supported should be
initialised in IDirect3D8Impl_FillGLCaps in directx.c.