bump miri to fix line endings on azure

pietroalbini · pietroalbini · commit dc9d2b34df21 · 2019-07-01T17:12:31.000+02:00
diff --git a/src/tools/miri b/src/tools/miri
@@ -1 +1 @@
-Subproject commit 72b2e1045d642c517347c421b1db92e34c22a70d
+Subproject commit d2df509867fbbbd35730c90aef54a8e73b046cd6
