Check for cyclicity in named mixin applications.

sdk/lib/_internal/compiler/implementation/resolution/members.dart

Index: sdk/lib/_internal/compiler/implementation/resolution/members.dart
diff --git a/sdk/lib/_internal/compiler/implementation/resolution/members.dart b/sdk/lib/_internal/compiler/implementation/resolution/members.dart
index 8043517e444cc077f232165c333282291f8fe848..465749d60b934309eda623481fe6eaeb5f195153 100644
--- a/sdk/lib/_internal/compiler/implementation/resolution/members.dart
+++ b/sdk/lib/_internal/compiler/implementation/resolution/members.dart
@@ -3513,8 +3513,10 @@ class ClassSupertypeResolver extends CommonResolverVisitor {
   }
 
   void visitNodeList(NodeList node) {
-    for (Link<Node> link = node.nodes; !link.isEmpty; link = link.tail) {
-      link.head.accept(this);
+    if (node != null) {
+      for (Link<Node> link = node.nodes; !link.isEmpty; link = link.tail) {
+        link.head.accept(this);
+      }
     }
   }
 
@@ -3534,6 +3536,12 @@ class ClassSupertypeResolver extends CommonResolverVisitor {
     visitNodeList(node.mixins);
   }
 
+  void visitNamedMixinApplication(NamedMixinApplication node) {
+    node.superclass.accept(this);
+    visitNodeList(node.mixins);
+    visitNodeList(node.interfaces);
+  }
+
   void visitTypeAnnotation(TypeAnnotation node) {
     node.typeName.accept(this);
   }