Fix invariant in reference type propagation.

Also some cleanups.

Change-Id: I7f0ec7d06b4bab10dbfa230c757447d311658f93
diff --git a/compiler/optimizing/nodes.h b/compiler/optimizing/nodes.h
index ecb690f..22551f5 100644
--- a/compiler/optimizing/nodes.h
+++ b/compiler/optimizing/nodes.h
@@ -509,6 +509,8 @@
   // before cursor.
   HInstruction* InsertOppositeCondition(HInstruction* cond, HInstruction* cursor);
 
+  ReferenceTypeInfo GetInexactObjectRti() const { return inexact_object_rti_; }
+
  private:
   void RemoveInstructionsAsUsersFromDeadBlocks(const ArenaBitVector& visited) const;
   void RemoveDeadBlocks(const ArenaBitVector& visited);