CMake: Add vorbisenc.c to vorbis target for WIN32 builds
On Windows the vorbis shared library exports some symbols defined in the
vorbisen.c file.  To allow error free linking this file should be added
to to the VORBIS_SOURCES.
@@ -57,6 +57,10 @@ set(VORBISENC_SOURCES
vorbisenc.c
)
+if(WIN32)
+ list(APPEND VORBIS_SOURCES vorbisenc.c)
+endif()
+
if(MSVC)
list(APPEND VORBIS_SOURCES ../win32/vorbis.def)
list(APPEND VORBISENC_SOURCES ../win32/vorbisenc.def)
