Canonicalize mixin applications by their name

pkg/front_end/lib/src/fasta/kernel/kernel_target.dart

 // Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library fasta.kernel_target;
 
 import 'dart:async' show
     Future;
 
 import 'dart:io' show
@@ skipping 176 matching lines @@
     loader.builders.forEach((Uri uri, LibraryBuilder library) {
       library.members.forEach((String name, Builder member) {
         if (member is SourceClassBuilder) {
           result.add(member);
         }
       });
     });
     return result;
   }
 
-  List<Class> collectAllMixinApplications() {
-    List<Class> result = <Class>[];
-    loader.builders.forEach((Uri uri, LibraryBuilder library) {
-      if (library is KernelLibraryBuilder) {
-        result.addAll(library.mixinApplicationClasses);
-      }
-    });
-    return result;
-  }
-
   void breakCycle(ClassBuilder builder) {
     Class cls = builder.target;
     cls.implementedTypes.clear();
     cls.supertype = null;
     cls.mixedInType = null;
     builder.supertype =
         new KernelNamedTypeBuilder(
             "Object", null, builder.charOffset,
             builder.fileUri ?? Uri.parse(cls.fileUri))
         ..builder = objectClassBuilder;
@@ skipping 384 matching lines @@
     superclass = superclass.superclass;
   }
   for (Constructor constructor in superclass.constructors) {
     if (constructor.name.name.isEmpty) {
       return constructor.function.requiredParameterCount == 0 ?
           constructor : null;
     }
   }
   return null;
 }