Nvidia and Mesa ignore GLX_RENDER_TYPE when it is set to an invalid
value like 0 but AMD for instance doesn't, which is legal.

The term "property" is misleading (ole32 has an unrelated feature
called a "property set storage"), and I haven't seen it used anywhere
outside the Wine code. The term "directory entry" matches the MS
documentation and more accurately describes their use in the file.

According to the MS spec, the types in compound storage files are simply
STGTY values, with an extra value named STGTY_ROOT for the root storage.

winex11: Implement AlphaBlend mode for the case where SourceConstantAlpha is combined with source alpha.

Tests show that it must not close the opened wave file.