CORD-2247: Write basic static checker for xproto

Change-Id: I63a96972e16fd8dd62d4dec840eede66cbb26368
diff --git a/lib/xos-genx/xosgenx/checkers/syncstep.xchecker b/lib/xos-genx/xosgenx/checkers/syncstep.xchecker
new file mode 100644
index 0000000..836a2c2
--- /dev/null
+++ b/lib/xos-genx/xosgenx/checkers/syncstep.xchecker
@@ -0,0 +1,5 @@
+{% for m in proto.messages %}
+{% if not m.options.no_sync %}
+{{ xproto_check_synchronizer(m) }}
+{% endif %}
+{% endfor %}