Add support for unresolved classes in optimizing.

Change-Id: I0e299a81e560eb9cb0737ec46125dffc99333b54
diff --git a/compiler/optimizing/graph_visualizer.cc b/compiler/optimizing/graph_visualizer.cc
index 7a83662..d38f4c8 100644
--- a/compiler/optimizing/graph_visualizer.cc
+++ b/compiler/optimizing/graph_visualizer.cc
@@ -501,8 +501,11 @@
         StartAttributeStream("can_be_null")
             << std::boolalpha << instruction->CanBeNull() << std::noboolalpha;
         StartAttributeStream("exact") << std::boolalpha << info.IsExact() << std::noboolalpha;
+      } else if (instruction->IsLoadClass()) {
+        StartAttributeStream("klass") << "unresolved";
       } else {
-        DCHECK(!is_after_pass_) << "Type info should be valid after reference type propagation";
+        DCHECK(!is_after_pass_)
+            << "Expected a valid rti after reference type propagation";
       }
     }
     if (disasm_info_ != nullptr) {