Fix handing of the following .idl snippet:

typedef [uuid(b14b6bb5-904e-4ff9-b247-bd361f7a0001)]
struct g { int g1; } g;

[uuid(b14b6bb5-904e-4ff9-b247-bd361f7a0002)]
interface test_iface : IUnknown
{
    HRESULT test([in] g *ptr);
}
Signed-off-by: Dmitry Timoshkov <dmitry@baikal.ru>
Signed-off-by: Huw Davies <huw@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>