Don't generate errors when failing to follow const constructor redirections.

editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/internal/object/GenericState.java

Index: editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/internal/object/GenericState.java
diff --git a/editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/internal/object/GenericState.java b/editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/internal/object/GenericState.java
index 8f1bffb26c558a67932e55bb5fa27af1c6cb1aaa..5eb51b83c3a5e13d0c7eb9980612f98dab0b5606 100644
--- a/editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/internal/object/GenericState.java
+++ b/editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/internal/object/GenericState.java
@@ -47,6 +47,15 @@ public class GenericState extends InstanceState {
   }
 
   @Override
+  public BoolState equalEqual(InstanceState rightOperand) throws EvaluationException {
+    assertBoolNumStringOrNull(rightOperand);
+    if (rightOperand instanceof DynamicState) {
+      return BoolState.UNKNOWN_VALUE;
+    }
+    return BoolState.from(equals(rightOperand));
+  }
+
+  @Override
   public boolean equals(Object object) {
     if (!(object instanceof GenericState)) {
       return false;
@@ -68,15 +77,6 @@ public class GenericState extends InstanceState {
   }
 
   @Override
-  public BoolState equalEqual(InstanceState rightOperand) throws EvaluationException {
-    assertBoolNumStringOrNull(rightOperand);
-    if (rightOperand instanceof DynamicState) {
-      return BoolState.UNKNOWN_VALUE;
-    }
-    return BoolState.from(equals(rightOperand));
-  }
-
-  @Override
   public String getTypeName() {
     return "user defined type";
   }
@@ -89,4 +89,9 @@ public class GenericState extends InstanceState {
     }
     return hashCode;
   }
+
+  @Override
+  public boolean isUnknown() {
+    return this == UNKNOWN_VALUE;
+  }
 }