Use unordered map hash on ConstructedConstantValue.

pkg/compiler/lib/src/constants/values.dart

Index: pkg/compiler/lib/src/constants/values.dart
diff --git a/pkg/compiler/lib/src/constants/values.dart b/pkg/compiler/lib/src/constants/values.dart
index 434fcfa8db99982b8e46809a1a73d64877debc1f..62749bf43ac4a866fc6c60203f549c8fdd6d9575 100644
--- a/pkg/compiler/lib/src/constants/values.dart
+++ b/pkg/compiler/lib/src/constants/values.dart
@@ -666,7 +666,7 @@ class ConstructedConstantValue extends ObjectConstantValue {
   ConstructedConstantValue(
       InterfaceType type, Map<FieldElement, ConstantValue> fields)
       : this.fields = fields,
-        hashCode = Hashing.mapHash(fields, Hashing.objectHash(type)),
+        hashCode = Hashing.unorderedMapHash(fields, Hashing.objectHash(type)),
         super(type) {
     assert(type != null);
     assert(!fields.containsValue(null));