Merge branch 'apriakhin/fix-xd-queue' into 'master'

Realm(bugfix): re-queue xd by pushing it to the back

See merge request StanfordLegion/legion!1574

(cherry picked from commit 3b43b2c)

e7c70f8 realm: re-queue xd by pushing to the back

Co-authored-by: apryakhin <pryakhin.artem@gmail.com>

runtime/realm/transfer/channel.inl

@@ -196,7 +196,7 @@ namespace Realm {
 	  {
 	    AutoLock<> al(mutex);
 	    was_empty = in_ordered_worker || ready_xds.empty();
-	    ready_xds.push_front(xd);
+	    ready_xds.push_back(xd);
 	    in_ordered_worker = false;
 	  }