Revert "Handle named mixin application in emitter"

pkg/compiler/lib/src/common_elements.dart

Index: pkg/compiler/lib/src/common_elements.dart
diff --git a/pkg/compiler/lib/src/common_elements.dart b/pkg/compiler/lib/src/common_elements.dart
index 6d25c75e635b07f2b48f410df2aefef5b9b703cc..4404b74645f2ea4cc826ce75fdd9cb346dbf6116 100644
--- a/pkg/compiler/lib/src/common_elements.dart
+++ b/pkg/compiler/lib/src/common_elements.dart
@@ -1254,9 +1254,6 @@ abstract class ElementEnvironment {
   /// Returns `true` if [cls] is generic.
   bool isGenericClass(ClassEntity cls);
 
-  /// Returns `true` if [cls] is a mixin application (named or unnamed).
-  bool isMixinApplication(ClassEntity cls);
-
   /// Returns `true` if [cls] is an unnamed mixin application.
   bool isUnnamedMixinApplication(ClassEntity cls);