winuser.h: move a misplaced #endif from end of the file to just after
the UpdateLayeredWindowIndirect() prototype. fixes bug #397, where
MsgWaitForMultipleObjects() was hidden when NOGDI is defined.
While we are there, adjust WM_MOUSELAST macro against WM_MOUSEHWHEEL
(cherry picked from commit 86cd97e495cc920e6f90345c9effea83a5bbb13d)