This is an internal wined3d function.

It's never used.

The failures in rpcrt4:server on Windows are caused by an access violation
thrown in NdrVaryingArrayUnmarshall() called from get_5numbers(). I've
created a minimum get_5numbers() test with Microsoft tools and that throws
the same access violation. The access violation disappears when zeroing
out the StubMsg before calling NdrClientInitializeNew(), so my guess is
Windows NdrVaryingArrayUnmarshall() uses an uninitialized member.