Request: User32 missing CallWindowProc function

[vyuzhanin]

WinAPI example: https://docs.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-callwindowproca

C# Example:

[DllImport("user32.dll")]
public static extern IntPtr CallWindowProc(IntPtr lpPrevWndFunc, IntPtr hWnd, PInvoke.User32.WindowMessage Msg, IntPtr wParam, IntPtr lParam);