After the fix for JDK-8285730 went in, the use of macros WINVER and IS_WINxxx that check for a particular WinAPI version becomes obsolete. One example is this group of declarations:
src/java.desktop/windows/native/libawt/windows/awt_Toolkit.h:157

All such uses need to be cleaned up in order to avoid confusion and reduce the risk of getting a compiler warning of unused declarations (which will break a "warnings-as-errors" build).