Handle fields with initializers in constant constructors.

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

Index: pkg/compiler/lib/src/constants/constant_constructors.dart
diff --git a/pkg/compiler/lib/src/constants/constant_constructors.dart b/pkg/compiler/lib/src/constants/constant_constructors.dart
index 129197f3dd01de426296d5c906755e4828854f42..4628f28629ef34f1e98467950eef14de9372289c 100644
--- a/pkg/compiler/lib/src/constants/constant_constructors.dart
+++ b/pkg/compiler/lib/src/constants/constant_constructors.dart
@@ -87,6 +87,11 @@ class ConstantConstructorComputer extends SemanticVisitor
     applyParameters(parameters, _);
     ConstructedConstantExpression constructorInvocation =
         applyInitializers(node, _);
+    constructor.enclosingClass.forEachInstanceField((_, FieldElement field) {
+      if (!fieldMap.containsKey(field)) {
+        fieldMap[field] = field.constant;
+      }
+    });
     return new GenerativeConstantConstructor(
         currentClass.thisType, defaultValues, fieldMap, constructorInvocation);
   }