This should make it clear it's not an external header.

It could be confused with mmdeviceapi.h, in particular.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=54819

There's the regular application icon and three different styles of
close window icons. While there is nothing wrong with that this case is
marked as broken() because Wine's notepad only has one icon so only 1 is
a valid PrivateExtractIconsA() result in Wine.

Needed for mingw Firefox build.

Needed by windows.ui.composition.interop.idl.