xwayland: Add and hook up test script

It runs XTS via piglit on (non-rootless) Xwayland on weston using the
headless backend.

Xwayland might use glamor if enabled in the build, but we're making sure
it uses software rendering.

v2:
* Use weston-info to wait for weston to be ready, instead of just a
  fixed sleep. (Martin Peres)
v3:
* Build wayland 1.18 & weston 9.0 locally, since the packages in Debian
  buster are too old for current Xwayland.

Acked-by: Olivier Fourdan <ofourdan@redhat.com>

test/scripts/xwayland-piglit.sh

@@ -0,0 +1,43 @@
+#!/bin/sh -e
+
+# this times out on Travis, because the tests take too long.
+if test "x$TRAVIS_BUILD_DIR" != "x"; then
+    exit 77
+fi
+
+# Weston requires XDG_RUNTIME_DIR
+if test "x$XDG_RUNTIME_DIR" = "x"; then
+    export XDG_RUNTIME_DIR=$(mktemp -d)
+fi
+
+# Skip if weston isn't available
+weston --version >/dev/null || exit 77
+
+weston --no-config --backend=headless-backend.so --socket=wayland-$$ &
+WESTON_PID=$!
+export WAYLAND_DISPLAY=wayland-$$
+
+# Wait for weston to initialize before starting Xwayland
+timeout --preserve-status 60s bash -c 'while ! weston-info &>/dev/null; do sleep 1; done'
+
+# Start an Xwayland server
+export PIGLIT_RESULTS_DIR=$XSERVER_BUILDDIR/test/piglit-results/xwayland
+export SERVER_COMMAND="$XSERVER_BUILDDIR/hw/xwayland/Xwayland -noreset"
+
+# Make sure glamor doesn't use HW acceleration
+export GBM_ALWAYS_SOFTWARE=1
+
+# Tests that currently fail on llvmpipe on CI
+PIGLIT_ARGS="$PIGLIT_ARGS -x xcleararea@6"
+PIGLIT_ARGS="$PIGLIT_ARGS -x xcleararea@7"
+PIGLIT_ARGS="$PIGLIT_ARGS -x xclearwindow@4"
+PIGLIT_ARGS="$PIGLIT_ARGS -x xclearwindow@5"
+PIGLIT_ARGS="$PIGLIT_ARGS -x xcopyarea@1"
+
+export PIGLIT_ARGS
+
+$XSERVER_DIR/test/scripts/run-piglit.sh
+PIGLIT_STATUS=$?
+
+kill $WESTON_PID
+exit $PIGLIT_STATUS