Do not emit substitutions for unnamed mixin applications.

sdk/lib/_internal/compiler/implementation/js_backend/emitter.dart

 // Copyright (c) 2012, 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.
 
 part of js_backend;
 
 /**
  * A function element that represents a closure call. The signature is copied
  * from the given element.
  */
@@ skipping 2011 matching lines @@
     if (checkedClasses.contains(cls)) {
       emitIsTest(cls);
       emitSubstitution(cls);
     }
 
     RuntimeTypes rti = backend.rti;
     ClassElement superclass = cls.superclass;
 
     bool haveSameTypeVariables(ClassElement a, ClassElement b) {
       if (a.isClosure()) return true;
+      if (b.isUnnamedMixinApplication) {
+        return false;
+      }
       return a.typeVariables == b.typeVariables;
     }
 
     if (superclass != null && superclass != compiler.objectClass &&
         !haveSameTypeVariables(cls, superclass)) {
       // We cannot inherit the generated substitutions, because the type
       // variable layout for this class is different.  Instead we generate
       // substitutions for all checks and make emitSubstitution a NOP for the
       // rest of this function.
       Set<ClassElement> emitted = new Set<ClassElement>();
@@ skipping 2001 matching lines @@
 
 const String HOOKS_API_USAGE = """
 // The code supports the following hooks:
 // dartPrint(message)   - if this function is defined it is called
 //                        instead of the Dart [print] method.
 // dartMainRunner(main) - if this function is defined, the Dart [main]
 //                        method will not be invoked directly.
 //                        Instead, a closure that will invoke [main] is
 //                        passed to [dartMainRunner].
 """;