[PATCH xserver] test: Run some XTS5 integration tests against Xvfb if possible.

[Adam Jackson]

On Wed, 2016-08-31 at 17:00 -0700, Eric Anholt wrote:
> By default the tests will be skipped.  However, if you set XTEST_DIR
> to the repo of a built X Test Suite and PIGLIT_DIR to a piglit repo
> (no build necessary), make check will run piglit's xts-render tests
> against Xvfb.
> 
> We could run more of XTS5, but I haven't spent the time identifying
> what additional subset would be worth running, since much of it is
> only really testing the client libraries.  We want to make sure that
> we keep the runtime down, and this subset of the test suite took 92
> seconds according to piglit.

I've got an xts branch around somewhere with some performance work.
I'll dig that up now that I've got an easy way to see where the time is
going (thank you piglit csv output). I seem to remember getting
complete xts runs done in around five minutes, we should be able to get
the rendering subset done in well under a minute.

Updated my pre-push hook to run this, and merged:

remote: I: patch #108292 updated using rev deae9c7e846e244e5d62b2dcfb6663fde0e12cbb.
remote: I: 1 patch(es) updated to state Accepted.
To ssh://git.freedesktop.org/git/xorg/xserver
   f06aef3..deae9c7  master -> master

- ajax