winlayer.c fails to build

[Harold Hunt]

> However, you will still need to apply the following patch, else
> the X Server
> will crash on startup if the WIN_LAYER_SUPPORT flag, in win.h, is set to
> 'YES':
> http://www.msu.edu/~huntharo/xwin/layerinit.c.diff

Do be aware that enabling the WIN_LAYER_SUPPORT flag causes the X Server to
give a STATUS_ACCESS_VIOLATION on shutdown.  That is a known problem, and
I'd appreciate it if someone would figure out how to fix it so that we can
enable layer support permanently.

Harold