--- a/src/hotspot/share/oops/method.cpp	Tue Sep 18 22:32:25 2018 +0200
+++ b/src/hotspot/share/oops/method.cpp	Tue Sep 18 16:11:36 2018 -0400
@@ -2152,6 +2152,8 @@
   if (value && !already_set) {
     MetadataOnStackMark::record(this);
   }
+  assert(!value || !is_old() || is_obsolete() || is_running_emcp(),
+         "emcp methods cannot run after emcp bit is cleared");
 }
 
 // Called when the class loader is unloaded to make all methods weak.