Support deserialization of ResolutionImpact for members of unnamed mixin applications

pkg/compiler/lib/src/serialization/serialization_util.dart

Index: pkg/compiler/lib/src/serialization/serialization_util.dart
diff --git a/pkg/compiler/lib/src/serialization/serialization_util.dart b/pkg/compiler/lib/src/serialization/serialization_util.dart
index 13184e9a486900c184a70f30d22f8b52c39b245b..24aa6f88ef58e2ba5f9f14109124f5e21d9b1548 100644
--- a/pkg/compiler/lib/src/serialization/serialization_util.dart
+++ b/pkg/compiler/lib/src/serialization/serialization_util.dart
@@ -4,6 +4,7 @@
 
 library dart2js.serialization.util;
 
+import '../common.dart';
 import '../constants/expressions.dart';
 import '../dart_types.dart';
 import '../elements/elements.dart';
@@ -474,3 +475,45 @@ AccessSemantics deserializeAccessSemantics(ObjectDecoder decoder) {
       throw new UnsupportedError('Unsupported access kind: $kind');
   }
 }
+
+/// Serialize a reference from [context] to an [element] which might be a member
+/// of an unnamed mixin application. If it is, [element] is by serialized
+/// indirectly by name in the [nameKey] of [encoder], otherwise [element] is
+/// serialized directly in [elementKey] in [encoder].
+void serializeElementReference(Element context, Key elementKey, Key nameKey,
+    ObjectEncoder encoder, Element element) {
+  if (element.isGenerativeConstructor &&
+      element.enclosingClass.isUnnamedMixinApplication) {
+    assert(invariant(element, element.isConstructor,
+        message: "Unexpected reference of forwarding constructor "
+            "${element} from $context."));
+    encoder.setString(nameKey, element.name);
+  } else {
+    encoder.setElement(elementKey, element);
+  }
+}
+
+/// Deserialize a reference from [context] to an [Element] which might be a
+/// member of an unnamed mixin application. If it is, the [Element] is by
+/// deserialized indirectly by name from [nameKey] in [decoder], otherwise
+/// the [Element] is deserialized directly from [elementKey] in [encoder].
+Element deserializeElementReference(
+    Element context, Key elementKey, Key nameKey, ObjectDecoder decoder,
+    {bool isOptional: false}) {
+  Element element = decoder.getElement(elementKey, isOptional: true);
+  if (element == null) {
+    String elementName = decoder.getString(nameKey, isOptional: isOptional);
+    if (elementName == null) {
+      return null;
+    }
+    assert(invariant(NO_LOCATION_SPANNABLE, context.isConstructor,
+        message: "Unexpected reference of forwarding constructor "
+            "'${elementName}' from $context."));
+    ClassElement superclass = context.enclosingClass.superclass;
+    element = superclass.lookupConstructor(elementName);
+    assert(invariant(NO_LOCATION_SPANNABLE, element != null,
+        message: "Unresolved reference of forwarding constructor "
+            "'${elementName}' from $context."));
+  }
+  return element;
+}