xorg-server 1.18 ready for testing on x86 and shark

[matthew green <mrg%eterna.com.au@localhost>]

hi folks.


i've gotten native xorg server updated to 1.18.4 and working for me
on i386, amd64 and shark.  more testing is needed.

to test, simply pass -V HAVE_XORG_SERVER_VER=118 to build.sh or set
it in mk.conf.

if you'd like to test, i recommend having a completely clean obj
and destdir for it (one of the failure modes is kdump not building.)
i also welcome help porting to other platforms, or updating drivers
(many older drivers are disabled with the newer server mostly due to
needing to be updated for modern xorg-server APIs.)

this also enables the xf86-video-amdgpu driver that supports modern
amd gpus.

as always, please send-pr to send me email about issues.


.mrg.