- psdk/mmsystem.h: Add a #ifndef guard around SC_SCREENSAVE, MS public headers have the same guard
- psdk/ole2.h: Add guards around CreateDataAdviseHolder that are similar to the guards used in MS public headers
- psdk/winuser.h: Add missing defines, use DWORD and LONG casts to fix test failures on x64. These same casts exist in MS public headers
- wine/test.h: Add defines for winetest_platform_is_wine, flaky, and flaky_wine. The flaky definitions depend on flaky_if, which is a stub that does nothing.