Fix for invalid 'extends/implements/with SomeEnum'.

pkg/analyzer/lib/src/summary/link.dart

Index: pkg/analyzer/lib/src/summary/link.dart
diff --git a/pkg/analyzer/lib/src/summary/link.dart b/pkg/analyzer/lib/src/summary/link.dart
index 67c5149995836fc7f1a3150fcd2d7f90422406d1..96eca0fae0adfe9ae88dbfa898cd322db79cd636 100644
--- a/pkg/analyzer/lib/src/summary/link.dart
+++ b/pkg/analyzer/lib/src/summary/link.dart
@@ -539,6 +539,9 @@ class ClassElementForLink_Class extends ClassElementForLink
       _unlinkedClass.interfaces.map(_computeInterfaceType).toList();
 
   @override
+  bool get isEnum => false;
+
+  @override
   bool get isMixinApplication => _unlinkedClass.isMixinApplication;
 
   @override
@@ -668,7 +671,7 @@ class ClassElementForLink_Class extends ClassElementForLink
   InterfaceType _computeInterfaceType(EntityRef typeRef) {
     if (typeRef != null) {
       DartType type = enclosingElement.resolveTypeRef(typeRef, this);
-      if (type is InterfaceType) {
+      if (type is InterfaceType && !type.element.isEnum) {

[Brian Wilkerson, 2017/01/28 17:18:39]

Then it could be used here.

         return type;
       }
       // In the event that the `typeRef` isn't an interface type (which may
@@ -732,6 +735,9 @@ class ClassElementForLink_Enum extends ClassElementForLink
   List<InterfaceType> get interfaces => const [];
 
   @override
+  bool get isEnum => true;
+
+  @override
   bool get isObject => false;
 
   @override