[PATCH 3/9] winegstreamer: Use nameless unions.

[Zebediah Figura (she/her)]

This doesn't compile for me:

leslie at terabithia:~/git/wine64$ make dlls/winegstreamer/winegstreamer.dll
   CC     dlls/winegstreamer/main.cross.o
../wine/dlls/winegstreamer/main.c:211:6: error: ‘REGFILTER2’ {aka ‘const 
struct __WIDL_strmif_generated_name_00000013’} has no member named ‘u’
   211 |     .u.s2.cPins2 = 2,
       |      ^

Note that we have the same problem as amstream/tests here; i.e. old 
versions of gcc can't handle nameless unions inside designated initializers.