Preserve canonical bit of static closures on reload.

runtime/vm/object_reload.cc

Index: runtime/vm/object_reload.cc
diff --git a/runtime/vm/object_reload.cc b/runtime/vm/object_reload.cc
index dd15a1f80c3ee74681469094f2b0d5452dea6ff6..f3b06e0da26669dc82984adeb761b7dabc6f1db6 100644
--- a/runtime/vm/object_reload.cc
+++ b/runtime/vm/object_reload.cc
@@ -392,6 +392,9 @@ void Class::MigrateImplicitStaticClosures(IsolateReloadContext* irc,
         old_closure = old_func.ImplicitStaticClosure();
         new_func = new_func.ImplicitClosureFunction();
         new_closure = new_func.ImplicitStaticClosure();
+        if (old_closure.IsCanonical()) {
+          new_closure.SetCanonical();
+        }
         irc->AddBecomeMapping(old_closure, new_closure);
       }
     }